One of the cars I own is a 1997 540i, and I had it recently supercharged with a Powerdyne Centrifugal Belt Driven (making it very quiet) Supercharger and a Vortech Fuel Regulator allowing it to work with the stock injectors. (No I did not have it supercharged by Dinan.) I added the 3.15 sport gears and a tri-flo exhaust. The numbers are showing 430hp up from 282hp stock. Road and Track published a 5.9 second 0-60mph and 13.9 second 1/4 mile with a stock 540i, automatic transmission. This car is faster than the M5. Now the question I have is that once those 540i owners all become supercharged what are the M5 owners going to do? The company that I purchased the supercharger from is introducing a supercharger that will also involve some intake manifold modifications and a series of other things, so the next question is, who is going to supercharge their M5? I know I am especially when the company is talking about 575hp.