[Perfectlap]

don't put your Boxster through a car wash unless you have hard top.
Even then I wouldn't do it more than once in a blue moon when its too cold
to do it yourself outside.
You don't want any soap or detergent on your canvas top. If you have done it get out the hose and rinse the top plenty to get out all the soap. I would suggest getting an oxo feathertip brush and brushing out the soap. You only want to use Renovo or Raggtopp canvas cleaner on your top.

on the RARE ocassion I visit a hand car wash, I tell not to soap up the top and I've gone so far as to give them a brand new chenille wash mits to use. I also don't let them dry the car. You're better off pulling over to the side and drying it yourself with a clean waffle weave. The use of dirty wash mitts and dirty drying towels are pretty much standard at every tunnell or hand car wash I have ever visited. Many cars are not clean after one pass through the car wash and are then dried which soils the drying towels which are then used on your car. Not to mention they use the cheapes quality (most likely to scratch) towels and mitts.