🎯 The business: a conveyor tunnel that washes a car in three minutes, sold mostly as a monthly unlimited membership. Two thousand members at $25 a month is $50,000 of revenue before a single car arrives, which is why private equity has been buying these. It is the most capital-intensive idea on this list.

Commuters on a busy arterial road who wash weekly without thinking about it. Single washes run $10 to $25; memberships $20 to $45 a month. Mature sites convert 60 to 70 percent of revenue to memberships, which makes the income steady through weather and seasons. A tunnel on the right corner can wash 100,000 to 200,000 cars a year.

This is a real estate deal first: traffic counts above 20,000 cars a day, a corner with easy in-and-out, and zoning that permits it. Then a lender who finances car washes, an equipment partner, and a membership launch plan that begins months before the water turns on. Visit ten tunnels in other cities and ask the owners about labor and chemical cost per car.

A site with 2,500 members at $28 a month and 3,000 retail washes a month at $14 grosses about $112,000 a month. Chemicals, water and power run around $1.50 to $2.50 a car, labor for a six-person crew $25,000 to $35,000 a month, and the loan on a $4 million project is the largest line. Mature sites commonly reach 40 to 50 percent operating margins before debt; new ones take two to three years to get there.

Zoning and site plan approval, stormwater and water reclaim requirements (often mandatory at this volume), building permits, sales tax on memberships in some states, and auto-renewal consumer laws for the subscription. Environmental review of the land. A lender will require all of it.

A second tunnel built across the street by a national chain with cheaper capital. Construction overruns. A membership base that grows slower than the loan requires. Damage claims on cars. The projects that work are on corners the chains wanted and could not get, with an operator who understands the subscription numbers as well as the wash.