sorry to ask about this topic but i have been searching for the last 3 hours and still cant find any answers.I just bought a 2000 m5 and i have the 4:3 screen and tape and i guess the mkII, i like the look of the widescreen so my question is can i upgrade to just the widesceen now and later look into getting mkIII or mkiv. Is the widescreen a plug and play in my car,will it work fine with the mkII nav.whats the diff beetween the mkII,mkIII,mkIV.