I owned a 2001 540i Sport 6 Spd and a 2003 M3 when I test drove a 2003 M5. I was instantly hooked. I searched and found one of the last remaining new 03s in CA. I have had the car for 3 yrs and it is the ultimate balance of performance, handling, comfort, reliability, and craftmanship. Furthermore, considering it is a 400 HP, 4000 lb sedan it is remarkably fuel efficient. I have averaged 21.5 MPG over the past 3yrs w/30K miles in mixed Bay Area driving. If you are looking for a remarkable automobile don't hesitate. You can pick up an immaculate and low mileage 2003 M5 for < $50K. This is a no brainer considering this is less than a new 530i or 335i. I have driven both and it is no contest.
Power, handling, ride quality, craftmanship and the sound and relentless pull of that 5 liter V8. It is a true super car.