I have a very poor system in the car at the moment, two speakers are holding the fort, both of which are pretty poor sounding. I need to completely re-wire the thing.

The first thing to overcome though is the head unit. Whenever it has a little bit of volume, and I'm not talking loud here, just a bit over talking volume, it cuts out. Now is this a dodgy connection or something to do with it cutting out under load? I'm sure I've heard something about the pre-amp inside the unit cutting out to prevent it damaging itself or something. But I'll be honest I don't really understand it so I'd appreciate any advice you lot could give me..

At some point, I'll be re-doing the whole thing, but this is my starting point!