Review on Roush 421642 Cold Intake Focus by Thomas Silva

Was skeptical about performance improvements, especially with such a small motor, but it actually works. Don't expect it to bang your head back in the seat, but there is a very noticeable improvement in the car's traction at higher rpm (HP), especially when trying to accelerate on the freeway. The downside is the sound. It's quite loud (especially when you hit the volume pedal), which was great at first, but daily driving just needs our style. Car, and not paying attention out loud, would say this is a definite upgrade.