just remember are you in the business of quick washes or complete details, do you think by offering specials for 5 and 10 dollars your going to attract quality customers that will come back and spend 100 to 200 dollars for a full detail ? can you afford to washes cars for 5 and 10 dollars ( i cant), the quick wash thing would be good if you had a drive through car wash (and you can knock out cars every 5 minutes), a car wash and detailing are really two different services/businesses......i personally will only wash cars for my very LOYAL customers, its not worth my time to do it but i know that customer will have me detail their car ever two or three months....
i only give deals and discounts to repeat customers that are loyal, if your looking to gain and grow business i always give customers a discount with two cars, you just have to ask yourself will 5 and 10 buck wash jobs give me quality long term money spending customers.......good luck