There is another thread I started in the tech & mod section with a link to the Evosport power package if you haven't seen it. The main reason I'm leaning more toward Renntech is the name and they only require three pulley's to be changed, but with the Evosport power package I believe there are six pulley's plus I don't think you can use your stock belt. I wish I had a friend with a dyno, Inmotion and I have e-mailed back & forth about their ECU upgrades, they are claiming up to 10% increase in h.p. I told them from the research I have done that was impossible without speeding up the supercharger. They got back with me and said they would sell me a pulley kit at cost and do my ECU for free if I dynoed the car before and after the kit installation and gave them the results. But it would probably cost more to have two dyno's done and paying them for the pulley kit than it would to just buy the proven Renntech kit.