I am very tempted to get this done as a few colleagues have had this done on their Impreza WRX STi Prodrive and Zafria 1800 and they have both said how good it is and what they are now noticing - smother, more refined and more poke, not to mention better mpg. The guy with the Zafria has gained 6mpg.
The colleague with the zafria goes home the same way as me and last night he was behind me and as I went to over take the car in front of me, he noticed a small puff of dirty exhaust gasses come out of the exhaust as I floored it. I have noticed that after I have cleaned the car inc exhaust, and driven 30 miles, the tips of the exhaust are dirty. So was wondering if terraclean might rectify this?