Stop washing the car, and approach her. Wouldn't you rather wash her?

You probably haven't asked her because you're thinking she might say "no." Well, she might, but you won't know until you ask her out.

Go talk to her...find out what she likes to do...offer to do it with her...

Bro, you got to let your balls drop and let the car have a rest.

You da man - go for it.