sambo,
give me a ring during the day and I'll have a chat to you. (0407 102 839)
the two above posters I have done recently one was scarey to look done by a local shop at the other was a recent job that wont go ANYWHERE without the owner knowing.
put the wheel on full lock and peel the inner guard out. that will invlove removing the mud flap and a few screws above it. it will reveal a grommet about the size of a fist.
got models?
most speakers will only handle 40-70w RMS (for get the big numbers they are just that , numbers.) so realistically an amplifier onf 75w RMS will drive all 4 nicely.