 I bought my 550i just a few weeks ago, and what an incredible ride that car, let me tell you.  Not only is it POWERFUL, putting you back in your seat, but it stops on a dime.  Having a "racing" background I can tell you that you need to get the 5 series for its handling and power delivery.  Everything else, just about is a plus.  The monster power in the 550i is invigorating!  Have fun!  Please just make sure that the Homelink garage door opener works before you drive it off the dealer.  Mine needed to be changed 3 days later.