About 4 years/50000 miles ago I bought a Scorpion exhaust for my mk2 GTI from Motech and recently noticed that one of the tailpipes had come loose due to a cracked weld on the inside of the backbox.
Remembering the "lifetime warranty" but not really holding out much hope I phoned Motech who asked me to fax my reciept and a copy of my reg document to prove I still owned the car. I did this on tuesday morning and yesterday a shiny new backbox appeared on my doorstep.
They don't even want to see the old one! Now that's what I call good service.