You're right, dealer protections like Supagard and Diamondbrite last until you wash it. The Scotchgard type fabric protector they supply is good though, I'm a fan of that!
My car was covered in Autoperfection sealant last month and the bugs come off with Lusso shampoo and a washmitt. Clay bars can be used to remove the really stubborn ones, if you've never clayed your car its well worth doing.
