M5 0-60 5.6 sec 0-120 21.9 sec
1/4 mile 14.3@99 slalom 63.4 mph
500E 0-60 5.5 sec 0-120 20.8 sec
1/4 mile 14.1@101 slalom 60.7
S4 0-60 6.1 sec 0-120 29.4 sec
1/4 mile 14.9@94 slalom 61.8

The M5 outhandled both the Merc and Audi and won the comparision. The Merc was also $24,000 more at the time. The Merc was an auto and was the fastest of the test but not by much.

Klaus

I'm thinking of buying a sleeper sedan. I'm down looking at the above two choices. I would appreciate the pluses and minuses of both cars. I believe the bimmer will be "sportier" due to the 5speed. but reliability and maitenance become issues. It appears the MBZ is more expensive but the "only common" problems are weaking PS pumps. What are the performance spec on the M5? Either car will be rebadged the m to 525 the 500 to a e260.