I'm really amazed by some of the ill-informed opionions stated on this last page regarding EPA compliance and engineers certificates. There is no workshop that can sell you a kit and have your car remain 'street legal'. As soon as you modify the car the onus is on you to have the car engineered to ensure compliance - no workshop can do this for you. As APS has stated (several) times mind you, they have had their kits tested in the various states of tune for emissions compliance. This is quite an expensive test, at least $10,000 to $20,000 if memory serves me correctly. Now APS have basically saved you needing to spend the same amount of money to prove that your car still meets these emissions standards, and you are having a go at them for it? It really amazes me..