first off if i were you the detailer would be paying for what ever happens but usualy you can pull the door window out with light force and slide a ruber wedge in. hmm any tow truck driver would know i was a lock smith for one year and we did it many times to norman cars but for a convertible theres no padding so you have to do it fron the back top right of driver window and with a 1/4 or smaller rod push the inside door lock and open button with a normal car there is a 1/4 inch rod that you use to lift the lock witch boxsters dont have so i would try the center consol button all try to get some pics of what to do 2 moro if you dont get any where. but any tow truck driver or locksmith should be able to do it very simple takes about 20 seconds pull window slide rubber wedge insert rod in the wedge
ps:the window should pop out of the cill its like when you open the door with out a battery it just uses some force to get it to pop open dont use to much force tho I would just call caa or in the US aaa? umm just incase here its free for a call
exactly like this here just there is no lock to pull so press center button
http://www.hightechtools.com/catalog.php?catid=1&objectid=21&productid=21
hope that helps good luck