I've got a 206 and it did the same thing in my car when I swapped over the CD player......it's nothing to do with your wiring because it plays so it's fine......its the wattage on the speakers that cant cope with the volume coming from the CD player........my car had standard 40 watt speakers in and I replaced them with 100 watt speakers and now I can blast the sound out on full volume and it doesn't cut out.......hope that helps!!!!
Stu
February 2007