[RandallNeighbour]

There are two oval covers on either side of your center map light. These are your motion sensors. I think every boxster has them.

When you have your top up and the hook is locked into place, or you have a little red clip installed like I do when the top is down so the sensor inside the hook's hole is depressed, and you lock the car with the remote ... the motion sensors come on automatically after a couple of minutes.

It's on a delay system so if you forget something you won't set it off immediately.

If you want to try and see if your motion sensors work, roll down the driver's side window, exit the car, lock it, drink a beer, then attempt to reach into the locked car through the window and remove something from the cubby under the radio. It should sound your horn.