I'm justs wondering about upgrading the stereo system on my 55 plate ICTDI. I currently have a fairly bog standard version (type b or c i think) just has radio, single cd. Am I able to just bolt on the ex system with satnav if i were to purchase a second hand one? Also are there any after market systems that would be worth looking at as well? If anybody has done anything similar in the past I'd love to know how easy/hard it was.