[toyotexan]

I just took delivery on my '07 and couldn't be happier. Of course now I have to start jacking with it. I have the factory 6 CD changer (not the premium JBL) and stock speakers. I want to start upgrading the sound but can't afford to shell out a grand all at once. Here are a few questions I have about this:

1. Would it improve the sound any by just replacing the front & back door speakers - any suggestions on which speakers to replace them with? Keeping in mind that eventually I will be replacing the receiver.

2. Does anybody know if the factory unit has pre-amp outputs? I have a subwoofer/amp box that I took out of my Ford F-150 that I can make fit under the rear seats.

3. I looked behind the rubber cover behind the back seats and found a wire with a female connector on the end of it that wasn't connected to anything. I tested it with an old speaker I had and got nothing. Is this wire just part of the stock audio harness and can I assume that the other end of this wire is hiding (unconnected) under the dash for the JBL setup? Or is this wire ready for an amp & subwoofer? (yeah right)

4. How difficult is it to remove the factory unit for inspection (I don't want to tear anything up doing this I just want to get a look behind it all).

Thanks for any input...great forum!