Please calm down guys. No need to continue a pointless discussion.

Back to the topic.

Matt you cannot compare top speed of M5 and RS4 based on the car's power alone. The gear ratios and the number of gears (7 versus 6) also plays an important role. If you want to tune a car for top speed you need other gear ratios than if you want to tune it for the fastest acceleration posible. Of course you can achive a balance between these two and that's what most sport car makers are doing.