That's exactly what I do!
My mates teenage son is autistic and he loves cleaning cars and is pretty OCD about it. He's learnt how to do it via youtube etc and has got himself all the gear. He cleans loads of cars on our estate and does a fantastic job. He'll wash the car, remove all the road grime such as tar spots, clean the wheels and tyres, machine polish and ceramic coat the bodywork, vacuum and clean the interior and treat the leather as well as clean the windows. He even vacuums stripes in all the carpets which is a nice touch and gives you an air freshener. And all that for £30! Cant go wrong really.