Hey guys, Going to be upgrading my exhaust in the first week of March as a birthday present to myself, Was wondering at the moment i just have a back box made by John Ashley Aldridge (not sure if anyone knows them) and im getting a cat-back system made up by garageDKU in wednesbury westmidlands ive been quoted £230 for the catback with 4" back box, 1 is that a good price? 2 what type of power gains (even if ever so slight) will there be over just a box? 3 whats the best sound to ask for as they make it to your own spec? Any advice will be much apreciated Peace out