You didn't by chance do the subs in the doors like this one did ya?
http://www.caraudioinnovations.com/installations/chris%20boxster%20s.htm
If you don't mind me asking what did you get done?
I've been thinking about upgrading so I can get XM and have been toying with the Navigation idea...not to mention I miss my bass. It was perfect in my last vehicle, nothing overwhelming just right. Clarion HU, with an Infiniti 12" Kappa Perfect DVC paired with an Xtant amp...the components from the factory were surpisingly good so I didn't have to touch those. It sounded perfect in the car, didn't vibrate anything on the outside...in fact you could hardly hear it outside the car...for me that's a good thing (I'm not a show-boaty type of guy.)