[Boxtaboy]

Here's your fix... I just recently had to do this as well. It's a $5 replacement part, but it is a bit of a pain to remove/replace due to the location of the sucker. You can try first just removing the ashtray and plate under it to spray some compressed air on the plunger in that Microswitch first to see if that fixes it.

http://www.bombaydigital.com/boxster/projects/parking_brake_switch/