Need System Upgrade Advice

Hi, right now I have a '97 Pontiac Grand Prix. I have a Kenwood head unit, 5.25 Eclipse speakers, and 6x9 Eclipse as well. System sounds great, and I'm pretty happy with it. In the next few weeks I'm getting a 1998 Lexus GS300. I took it into the audio shop today to have em take a look at it and what i was told is that because of the door constuction on the lex it would be a real pain in the ass to use any of the speakers i have now. The guy suggested replacing the stock sub and amp and that would be my best move. Does anyone here have any other possible reccomenations about my situation? If someone could reccomend some specific equipment to look for I would really appriciate it. Also, is ebay a legitimate place to look for equiment at?

Ebay's fine *if* you know what you're looking for & and sure of it, and you're comfortable with the Ebay process.  You won't be able to audition or return anything thru Ebay.  But for God's sake, don't go to the local shop, take their time auditioning & asking advice and then go to Ebay - that's just wrong.

Yeah, im pretty loyal to these guys, ive had them do other instalations for me and im very happy with their service. Thanks for the reply

your new ride uses 5 .25" speakers front and rear. So use the pair you got now and get 1 more set for the rear. Big Dave