First off - welcome to the forums with your new ride.
Do try to read through some of the existing threads here before posting new questions, so as not to repost commonly asked questions.
Here's a previous thread on washing the convertible:
Solara Convertable and Car Wash
Here's some info on keeping the top clean as well, as discussed in another thread:
Convertible Top
Good luck and have fun with that new rag top!
Jeff