Hi Timmy, I had a C1 for a year and a half and changed the speakers in the first month or so. I put two 'Alpine SXE-1025S 10cm Speakers' from Halfords in the front (itemcode: 680884-0) and I cut two holes in the back parcel shelf for two decent sized (150w 3 way) Sony speakers. My C1 which was a 2006 had enough speaker inputs no problem. You can tell by seeing if you have a 'Fade' feature on the radio. Nitty Gritty bit - in order to install the fronts, I had to carefully cut two of the speaker mounts off the new Alpines in order to make them fit. Very very easy. BUT - then I found with all my new speakers that the headunit was still weak despite all this extra capability. So I went on Ebay and bought a C1 headunit adapter fascia and slotted in my own 150w JVC (with 400w amp in the boot and a 10" subwoofer!!). Then the car sounded excellent!! Incidently - I have the JVC (mp3) headunit, C1 Fascia, Amp and Sub for sale if anybody is interested!! Sounds amazing in a little C1 :P **EDIT** Should add that the reason it was taken out is because I bought a C2 airplay this week!!