i think your buddy exaggerated about spending 15k on his escalade's sound system and 5k on his VW R32. from what youre describing, he thought dishing massive amounts of money meant having a superb system, and that's not what it's about. i wouldnt be surprised if my 800 dollar system sounds better than his 15,000 dollar system from what you're saying. he seems to be a basshead and although theres nothing wrong with that (that's his perogative), don't let his system influence. if he really did, spend 15k on that system the only lesson here is that you cant just throw high-end equipment in and expect it to be heaven-sent.. tuning is the bigger role in the end result and will be the biggest factor in the overall SQ, but im sure u know that. you seem knowledgable enough to come to your own conclusions so i'll leave u with a few pointers..
1) i prefer sticking to one sub so that means you should to //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif
2) dont chop up your porsche for manhood-sake
3) try to keep a factory look as possible
4) invest in some fine proccessing to really bring out your system