GaryCat

I want to add a small 4-channel amp into my '03 WRX but don't want the hassle of running new speaker cables through to all the doors. So, would the standard speaker cables be able to handle about 40w RMS?

Alternatively, does anyone have any hints & tips for installing an amp?

ru'

The standard stuff would 'be able to handle it', but it's pretty puny to be honest.

chiark

Run the cable - it's worth it. There's a grommet in the car side of the door jamb that is easy to come out of, then go into the OEM boot. Seal with silicon, and Robert is your father's brother.

evolutionice.com

the standard wiring is good for around 30-40watts per channel. If your looking to fit a decent system then its worth the extra effort. Use 1.5mm for front/rear speakers,2.5mm if your using 6x9's in the rear and 2.5(up to 150w)/4mm(above 150w) for the sub.