A part of the gearhead culture is always wanting to perfect and improve a car. Sometimes, a vehicle is best left stock, sitting nice and purdy on all original parts. There's always a power-hungry part of us that says that's just unacceptable, though. That's where tuners and aftermarket customizers come in. There is an entirely different culture, once you step into the garages of places like Wheelsandmore, HAMANN, and Underground Racing. With all of the carbon fiber, body kits, exhaust systems, and turbos you can handle, here are The 25 Best Custom Cars of 2012.