Hi, i'm new to the forum and hoping to benifit from your advice. i have just purchased a 07 C50 and i'm looking to upgrade to some performance products. i have purchased vance and Hines Street shots exhaust along with a K&N air filter and Power Commander but i have heard the power Commander is not neede by a few service techs. i am looking for experience and advice from anyone on this situation before i continue on with the installation.