Thanks for the replies, guys!

I am a big time DIYer, so buying parts online and doing the replacements in my garage is no big thing to me.

As for the third row, it will mostly be used for children, as I have an 8 year old and a 5 year old who will likely be back there, and any car seats will end up in the middle row. I'll make sure that I get a good feel for the legroom back in the back though. that's a good point, Savant. Thanks!

Conedoctor, what is this other inline six of which you speak? I know of the NA N52, I know of the twin turbo N55, and I know of the diesel, not to mention the X5M (totally not interested in the M, unfortunately.)