Really, I've had no problems with them. I ordered my PWR radiator through them and everything. They do good prices for me. Herrod has nothing to do with Knox ford anymore. The only issue I have had was on my high tune (281rwkw) it started to ping but that could be the Sh*ty shell near my house which I refuse to fill up from these days. I like stainless so I don't have to worry about it rusting away, going to darwin next year... And it's not a looks thing with stainless cause I run 17's territory rims painted black. But I like the look of the qauds Where do you work, I swear I have seen your car out watsonia way. I work on Simpson Barracks. I might go down a talk to the exhaust shop, did you have to retune your car after you put the quad system on? I'm just about done anyway save shocks and brakes....