Always clean car on purchase. Then clay bar, poorboys and ten wax. I never let the stealers clean the car, i put a post it note on the steering wheel saying do not wash!
The MB dealer in Brisbane Australia had a team of nubile young ladies that washed the cars (they were subcontracted from an all girl business). They couldn't understand why they were not allowed to touch my car.
All my cars are not garage queens, use them as they should be used, rather spend my time driving than cleaning