All

I am new to this forum but not new to BMWs. I currently own a 1995 e36 vert and a 2004 330i ZHP. Indeed I have owned and worked on BMWs since my first e30 back in 1990. Anyway, I am about to look at and possibly purchase a CPO 2007 x5 3.0si. I was initially interested in a 2005 or 2006 as I am very familiar with the M54 inline 6 engine. However, my wife just loves the look of the the 2007. I must admit that I like it's look also. Anyway, are the 2007s more difficult to work on for a home mechanic than the m54 engine. How reliable is the 2007. What mechanical problems can I expect? I assume BMW still has not taken care of the cooling system? What else should I be looking at?

We are looking at a CPO Platinum Metallic Bronze X5.