Start at the beginning. Is there still a need for a carwash at this site location?
Arguably, there is still a need for c-store and fuel because the store remains open.
However, why has the wash been closed for 4 to 5 years?
Operators normally abandon a business when sales are less than fixed cost.
Average cost of capital is $4,000 a month plus $6,000 or so for direct labor cost.
Operating expenses (per unit variable cost) is about $1.50. Average price is about $7.00.
So, breakeven point is about 9,500 units.
Conservative gas/wash rate today is 150.
Gallons per month = (9,500 X 150) / 12
Gallons per month = 118,750 to breakeven
So, sanity tests are how likely are sales greater than 118K gallons per month and/or gas/wash rate less than 150 (less means better)?