Yep spot on Ben, probably the speakers causing the problem now. First
thing to do is always replace the factory fitted radio, next is the
speakers or add a sub to give better sound. You could check out Car
Audio Plus for some speakers, I have a link from my blog www.blogcaraudio.co.uk
top banner, mid way down the left hand sidebar. Hope it goes well,
post up your progress.

Best Regards
Ged
www.blogcaraudio.co.uk