Help with Purchasing a 2004 X3..

[MarvenX3TO]

Hi folks,
I was looking a used 2004 X3 CPO vehicle or from a small time dealer. Well I've come to the conclusion that CPO vehicle will be better. Although the regular dealer is asking quite a bit less they are high milage. Well over 80K (50k Miles)..the lower milage ones are pretty close to BMW CPO ones. Plus a CPO vehicle offers roadside assistance and a much lower finance rate. In any case I have a few questions if someone can help..

• I am getting a Auto - will I be ok? I am being told by BMW that this is covered by CPO and is a SW issue not a mechanical one.
  Athough I dont want to be in the shop all the time. Should I be getting a 2005 instead??
• Can I add the AERO kit to a 2004, if so where can I get it? I think I can but I've been looking everywhere and searching threads but it isnt clear.
• Can I add Bluetooth and Ipod functionality? I think Dension has units (http://www.dension.com/GW100.php) or I might get a NAV with it built in..Anyone have any experiance with a built in NAV unit or Dension?
• If I can add it any one know where I can get it done in the GTA?

I know there are some answers to these but they are not clear. Please dont flame me with a search answer ;-)