I've mine a few months now. Hasn't giving any major trouble but they have 1 or 2 little faults. Early models had problems with drive shafts (think fords upgraded them in mid 06) thankfully mine has the upgraded one's

also they have a warranty problem with the seal in the dip stick. Some of them have been known to leak oil. With the issue of fuel it's a 2.5 turbo car so it's going to drink the petrol. Best purchase you can get is a dreamscience handset. Just plug it in and it makes a very noticeable difference.