You dont know anytihng about m5s do you? Comparing a crappy 545i with m5 lol I owned a 545i 2005 here in sweden and my friend has a m5 580bhp hartge edition let me tell you this you cant compare it in anyway its a totally different car even chassis are not same underneath. Just a little bit identical but that too you can see clearly how big of a difference m5 is from a 5 series The v10 that comes in m5 is a beast and the ride is fast as hell and kills c63 amg,Ferrari 360, lamborghini gallardo and other rides easily.