Do they want mobile or prefer a shop to drop the cars off with? IME they don't want you on their property, just the clean cars
Also, it seems like you'll alienate your retail clientele (someone said it best-the business professional who just wants a super clean car and willing to pay whatever you want). You can do both without alienating your retail customers but you need to do wholesale work somewhat differently to be profitable. Tough to teach employees two different styles sucessfully
Also, why would a dealership rather payout $100+ per car to a shop when they can hire an inhouse person for $10-$15/hour? B/C they don't have to deal with an employee and all the related expenses and headaches. Also, most dealerships do have detail staff but use outside shops for overflow.
Finally, what dealerships are using shops? Is it the big retailers selling brand new cars? Or is it mid-size companies doing used sales or is it very small, corner-lot kind of companies who have 10 year old beaters.All of the above, usually. The dealer I work for uses us for trade-ins and auction cars while their staff does the new car preps and deliveries.
