Installed my Pioneer 80prs yesterday, but the dimmer feature doesn't seem to work

[nrubenstein]

yup I know. I'm just not sure how much those stock speakers can handle. The 80prs said it pushed out 50W RMS.....I left 2 channels of the amp capped, so if I decide to do it, I will splice it to the amp wiring in the trunk. I'm actually very satisfied w/ the sound for now. I just adjusted the fader slightly to the front to compensate.

And yes painting the trim made a big difference imo....I think it blends in w/ the dash a lot better. I sanded it slightly, applied a couple coats of Duplicolor etched primer & Duplicolor trim paint (which I used to shadowline the exterior E30 trim).

You misread that. :) It's around 50W peak, and 20 or so RMS. Plenty to run the rears, but there's no reason not to have some headroom for the fronts.