Re: GTA breaker
They've been doing a supercharger mod for ages, only problem is it costs about £4k and I expect you don't save a huge amount on fuel. I don't know exactly which parts they replace in the engine, but the extra pwer will cause a lot of extra stress to the engine and surely shorten it's lifespan.
I did email them asking these very questions about longevity etc. a while back when I was considering the turbo upgrade on the spider and they never responded (I emailed them more than once too)