Bought the car with 140K and drove it home (eBay...1000 miles away) getting 28 MPG all the way. I thought I wanted a 540i till I saw the MPG. Kept it mainly as a road trip vehicle for a year, then started driving it daily. Here we are 2 years and 25000 miles later. My only monetary investment has been tires, brakes, a/c compressor, spark plugs and a radiator. Not bad for a car with 166,000 miles. Still runs very strong, corners like a dream, great curb appeal. My wife tries to trade vehicles with me on an almost daily basis (Grand Cherokee Overland). The valets all ask me to let them know when I may be selling it!
Driving comfort, timeless lines, MPG, road feel, brakes are awesome, cornering, durability, reliability, turbine smoothness, broad flat power curve, enough trunk space for several bodies (or so I am told), full size spare, factory sound system is pretty good, factory tool kit is actually useful!
A little more power would be good, as well as a little better support with parts for the older cars. I find some parts are easier to get from friends in Europe than through the dealer.