How to Underwrite a Car Wash Acquisition in 2026: An IC-Grade Framework

After running buy-side and sell-side advisory across $200M+ in closed transactions, the underwriting framework I use is the same one I'd run for an institutional investment committee. Six numbers that tell you whether the deal works. Five red flags that tell you to walk. Anchored to the actual 2025-26 transaction market.

The 2025-2026 market context every buyer needs to know

Before you put pen to paper on a bid, you need to know where the market is pricing AND what the multiple is actually measuring. The single biggest framing error in car wash M&A is conflating multiples with and without real estate. They are not interchangeable.

With real estate vs without real estate

OpCo-only deals (no real estate, typically because the seller has already sale-leasebacked the property or the buyer is acquiring a leasehold operating business): EBITDA is measured after rent expense, so the EBITDA is lower and the multiple is correspondingly higher. This is the basis most platform-level transactions trade on.

OpCo+PropCo deals (operating business plus the owned real estate): EBITDA is measured before rent (because the buyer now owns the real estate and pays no rent), so the EBITDA is higher and the multiple is correspondingly lower. The real estate component typically trades at a NNN cap rate (6.2-6.5% in early 2026), which is roughly equivalent to a 15-16x multiple on the rent line.

If you don't specify which basis a multiple is on, you don't have a comparable. Period.

Current pricing, basis-explicit

The bubble peak of 2021-22 (platform OpCo-only deals at mid-teens to 20x+ EBITDA) is over. Current comparables, by basis:

• Platform deals (multi-site portfolios with proven membership economics), OpCo basis: 9-11x EBITDA is the current range, with the best portfolios going higher. Whistle Express acquired Take 5 Car Wash from Driven Brands in April 2025 for $385M across 385 units. That transaction was largely OpCo-only — Take 5 had previously executed substantial sale-leasebacks of the underlying real estate — so the headline ~8x optics understate where comparable membership-anchored platforms with full corporate infrastructure would trade. Premium portfolios with institutional-quality membership economics are clearing 11-13x OpCo today.
• Public-comparable benchmark: Mister Car Wash announced its take-private to Leonard Green & Partners in February 2026 at $3.1B enterprise value, an NTM multiple of approximately 11.9x per public analysis. That's the institutional anchor for a 500+ site platform with disclosed best-in-class membership economics.
• Small portfolios (3-20 sites, membership-anchored), OpCo basis: 6-8x EBITDA. OpCo+PropCo basis: 5-7x.
• Single-site express tunnel, OpCo+PropCo basis (the way most single sites actually transact): 5-7x EBITDA for a typical site; 7-8x for well-performing sites with strong membership and owned real estate in tier-one trade areas.
• NNN-listed single-site real estate is trading around a 6.2-6.5% cap rate as of early 2026, with cap rates compressing through 2025.
• Industry-wide BizBuySell aggregate (all formats, including IBA and self-serve, mostly small operator-to-operator deals): 2.7x-6.9x EBITDA.

The compression-to-build-cost insight

At current single-site multiples on an OpCo+PropCo basis, there are markets where you can buy an operating express tunnel below replacement cost. The math:

• Replacement cost (all-in greenfield build, Southeast US, 2026): $4.0M-$7.5M depending on land, site work, and equipment package
• Acquisition price (single site, $800K-$1.0M EBITDA, 5-6x OpCo+PropCo): $4.0M-$6.0M

When a stabilized operating asset with proven trade-area performance is trading at or below the cost to build the same asset, that's compression — and it's a buy signal. You're acquiring de-risked cash flow with an established membership base and operating history, at a basis that doesn't require Year 1-2 ramp risk. The 2021-22 capital cycle pushed multiples so high that buy-vs-build math heavily favored build; the 2025-26 reset has flipped that for the right targets.

The corollary: if you're modeling a greenfield build in a market where comparable stabilized sites are trading at or below replacement cost, your underwriting needs to demonstrate why the new site will outperform the comparable, not just match it. Otherwise, buying is the better risk-adjusted move.

Direction of travel

Multiples compressed through 2022-2024 as rates rose, then firmed up in 2025-2026 with BizBuySell showing aggregate multiples increasing again. The bid-ask spread between premium (membership-rich, clustered) and average sites is widening. The market is bifurcating: best-in-class platforms trade at 11-13x OpCo, average single sites at 5-7x OpCo+PropCo, and the gap between them is meaningful.

Two market signals that should anchor your underwriting:

• ZIPS Car Wash filed Chapter 11 in February 2025 with $654M of debt and 260 locations. The CEO publicly cited oversaturation from "900 new car washes annually." That's the downside scenario for a leveraged platform.
• Driven Brands exited the US car wash sector entirely by selling Take 5 to Whistle Express. That's a sophisticated sponsor concluding the risk-adjusted returns don't fit their portfolio strategy. Their analysis isn't necessarily yours, but read the reasoning.

The six numbers that matter

1. Revenue quality, not revenue total

Two washes can do $2.4M in top-line revenue and have radically different value. The split is what matters.

• Membership revenue as a % of total wash revenue: Above 70% is institutional-quality (Mister Car Wash runs 75-76%). Below 50% means you're buying a retail business with a car wash attached.
• Average ticket on retail: Below $12 means you're competing on price. Above $18 means you have pricing power.
• Cars per day (CPD) consistency: A wash doing 250 CPD with 5% weekly variance is worth more than one doing 280 CPD with 35% variance.
• Member ARPM: The 2026 benchmark is $29.56 (Mister Q3 2025 disclosure). Rinsed industry average is approximately $30. Below $26 signals pricing weakness; above $35 deserves verification on tier mix.

Pull 24 months of POS reports. If the seller can't produce them, the deal isn't ready for diligence.

2. EBITDA quality, and the seller's add-backs

Every seller has add-backs. Half of them won't survive scrutiny.

Legitimate add-backs I'll accept:

• One-time legal/professional fees
• Owner compensation above market for replacement GM
• One-time equipment repairs that won't recur
• Marketing experiments the new owner won't continue

Add-backs I won't accept:

• "Personal vehicles" running through the P&L
• Family member wages with no documented role
• "Future cost savings" the buyer hasn't actually committed to
• Maintenance that the buyer will absolutely have to spend

3. Membership penetration and churn

Penetration measured two ways: members ÷ unique monthly customers (operator view), or member revenue ÷ total wash revenue (public-company view). Use both.

• Member-revenue % above 70% of wash revenue: Institutional-quality, matches Mister Car Wash's disclosed level.
• 8-12% members-to-customers penetration: New site or underperforming. Upside opportunity.
• 12-15%: Healthy mature site.
• 16-18%: Strong operator.
• 20%+ penetration: Best-in-class. Confirm with raw data, not seller claims.

Churn is the more important number nobody asks about. Rinsed's Q4 2025 industry aggregate is 7.6% total monthly churn (4.6% voluntary + 3.0% involuntary credit-card). Mister Car Wash runs approximately 5% monthly as a best-in-class benchmark. I underwrite to the industry aggregate (7.6%) even when the seller claims best-in-class, then build the upside case to 5% as proof-of-improvement potential.

4. Trailing 18-month capex (not 12)

Sellers love trailing 12 months because they suppress capex in the run-up to sale. Trailing 18 catches that.

What I look for:

• Tunnel equipment replacement cycle: Belts, brushes, dryers, chemistry pumps. Budget $0.08-$0.12 per car for routine recurring capex on a well-maintained site, $0.25+ per car if equipment is aging or has been deferred.
• Vacuum motors: 7-10 year replacement cycle, $400-$600 per unit installed.
• Pay station refresh: 8-10 year cycle, $25K-$45K per lane.
• Reclaim system service: Annual deep service plus 5-year filter/pump replacement.

Useful-life note for the major equipment families: properly maintained tunnel structural equipment routinely runs 15-20+ years with periodic rebuilds, but the actual financial risk is parts availability and component rebuild intervals, not metal fatigue. Request maintenance logs and recent rebuild history during diligence rather than relying on generic published intervals.

If the seller's recurring capex is below $0.05 per car, something has been deferred and you're going to find it within 18 months of close.

5. Working capital and deferred maintenance

This is where deals die quietly in diligence.

Pull the membership unearned revenue liability. If a wash has 4,800 monthly members at $25/month and no unearned revenue on the books, the seller is running the business on a cash basis and you'll inherit obligations you can't see.

Walk the back of house twice. Once with the seller, once without. The second walk is where you find the corroded chemistry containment, the cracked underground utility vault, the tunnel bay that floods in heavy rain.

6. Real estate, own, lease, or assignable?

Ground lease deals can be excellent, but the lease terms drive valuation more than the operating performance.

Lease deal-killers:

• Term under 15 years remaining (including option extensions)
• Rent above 8% of gross revenue
• Assignment language that requires landlord consent without reasonableness standard
• Recapture clauses on operating data

Sale-leaseback strategy note: Mister Car Wash executed $134.9M of sale-leasebacks in 2024 specifically to free real estate capital while maintaining operating control. The structure is now standard for sophisticated multi-site operators.

The five red flags that make me walk

1. POS data the seller won't release pre-LOI. A serious seller produces 24 months of raw POS exports within 5 business days. Anything else means the numbers don't hold up.
2. Membership pricing change in the last 12 months. Recent price increases artificially inflate trailing revenue and mask churn (Mister's January 2025 price increase normalized in 4-6 weeks, but most operators don't have that brand strength). I model the deal at the prior pricing to see what the run rate really is.
3. Equipment past its second rebuild cycle without documentation. Tunnel structural equipment commonly runs 15-20+ years, but component-level rebuild history matters. ICS controllers have an 8-10 year refresh cycle; pay station hardware is a 7-10 year capex line. Past the second rebuild without records, you're buying replacement risk priced as operating equipment.
4. Trade area saturation accelerating. Pull permit data for the last 24 months in a 3-mile ring. Apply the DRB market saturation framework (under 1,500 cars per existing tunnel wash equals oversaturated). If two or more new tunnels are under construction or recently opened, the trailing revenue won't hold and your pro forma is broken before you close. ZIPS Car Wash's February 2025 bankruptcy was driven by this exact dynamic.
5. Seller financing required to make the deal work. If the bank won't fund the LBO without a meaningful seller note, the deal is overpriced. (Take 5 is an exception: the $385M Driven-Brands-to-Whistle transaction was structured as $255M cash plus $130M seller note, but that's a strategic divestiture between sophisticated sponsors, not an operator-to-operator sale.)

How we structure the IC memo

Every memo we write at WLG follows the same structure:

1. Deal summary, 1 page, the numbers a partner needs to decide whether to read further
2. Property and operations overview, 2-3 pages with site photos, equipment list, P&L summary
3. Trade area analysis, demographics, traffic, competition (DRB saturation framework), growth indicators
4. Financial analysis, historical P&L normalized, pro forma, sensitivity tables
5. Valuation, comparable transactions (anchored to 2025-26 platform comps), DCF, multiple analysis, recommended bid range
6. Risk factors, honest list, no marketing language
7. Diligence checklist, what we'd verify in confirmatory phase
8. Recommendation, pursue at X price, walk above Y price

How we apply this at WLG

We've run this framework on 60+ acquisition targets across the Southeast. We turn down more deals than we recommend. The ones we recommend close at our bid range about 70% of the time. The 2025-26 market is unforgiving to overpaid deals; sticking to the framework matters more than it did in 2021.