There's a hand car wash in Commack on Jerico Turnpike right after it forks into 347/454 going east bound. I had my car washed there, but never detailed. It's actually a funny thing to see. It's like a regular automated car wash with the track that pulls your car through, but all the machinery is pulled out except the air dryer at the end. (They still dry your car by hand afterwards.) Instead, there's an assembly line of people standing in there with rags and soap. Their parking is usually packed with tons of cars there waiting to be detailed. I don't know how good they are at detailing, but I know the dealers in the area use them.