Thanks to the guys that replied to my tuning question for the 3.8 engine.
I was looking through the past messages about adding nitrous oxide to an M5 and there seem to be mixed feelings.
Surely on such a well built engine that the M5 has, it would not be too risky to run a six nozzle kit (one for each cylinder) and a rising rate fuel regulator, with only a 60 bhp increase. Obviously it would have to be correctly set up, fuel pressure, Nos boost and timing to combat detonation.
Hmm... 340 + 60 = E39 BHP, could prove interesting with the little white clip removed from a certain cable under the bonnet hehe.