However if you dont want to amp all your speakers ^^, you can run aftermarket speakers with decent wiring from the head unit, i currently run spl dynamics components in the front from the head unit, and some cheap edge 4 way coax's in the rear again off head unit, it sounds pukka, i also fitted my old faithful sony silver pentagon sub in the boot, and i'm running that from a 2 channel 600w amp, i also used decent sound deadening around the speakers to minimise on rattle!
here's my current setup in a twingo (pretty much a mk2 clio underneath):
Got a sony cdxgt530 head unit which didn't cost me a pennty
these up front with dynamatting connected to an old alpine crossover i had laying spare
these in rear:
my boot:
All in all the sony sub i've had for yonks, got it at a super cheap rate due to a till f**k up in halfords 4 years back lol, head unit came from my cousins car which he wrote off, the amp i got for a bargain price brand new on ebay, front speakers cost me around 40 and rears 25, its not the best stuff in the world but i can't fault it
Prab