Some time ago I was considering purchasing a 2002 M5 E39 and took it to a pre-purchase inspection and the results were insane. The car needed $12k in maintenance just to get the car reliable and not burning through tires (due to bushings). That also included a new (used) 6-Speed Transmission because the one in the car was singing like a bird! I decided to take it to another shop for a second opinion. So I headed over to Edge Motorworks in Mountain View, CA and they also quoted me $12k! Holy Crap. So I inquired what should I look for as an alternative and they suggested the 540i M-Sport 6-Speed without blinking an eye.
Many BMW enthusiasts lust after the E39 (1999-2003) M5. Simply put the M5 is a fantastic car, but for a fraction of the price and a fraction of the reliability problems you can get a vehicle that has 90% of the performance. The E39 540i M-Sport is that vehicle. Made throughout the E39 build cycle, the 540i from 2003 is considered to be the best of breed. Earlier variants had 5-Speed manuals and various odds and ends, but the 2003 variant has all the bells, whistles and that sick M-Technic aero kit that looks very similar to the big brother M5.
Using BRZO you can quickly find a number of good looking examples of the 540i M-Sport and it is likely that many of these were well pampered. Here is a video on how I search for these cars: