Well...add a shaft drive and you certainly will up the weight! The BMW system is quite complex to avoid the rear end rising on acceleration and would entail a major re-engineering of the M3W rear suspension.
I did say earlier that lubrication of a chain would be a pain but then we Classic owners think nothing of greasing the front suspension every thousand miles and I read very recently about a solid graphite grease block that lubricates motorbike chains for several thousand miles before replacing. So on second thoughts, I'd go down the chain route.
Jays Former Morgan owner. Gone but hopefully not forgotten!
