Yep the Mangoletsi modification is pretty much the only one in England that several of us have and can vouch for, and it is very good. Car sounds way better, has better throttle response and develops more torque and power, with better fuel economy too. Only thing is Mangoletsi are in Cheshire, M6 J19, but it is well worth the trip - I went from Wimbledon there and back in one day, takes an hour to fit, well worth it. They call it "mod 4". See the threads in the tuning forum - "Mangoletsi Performance Weekend August" - has all the info and they are holding the discounted prices for us til end of year.
Brat Pack no.8