Among the factory muscle cars of the late 1960s, few are as obscure yet as technically ambitious as the Mercury Cyclone Spoiler II. Marketed as a limited-production street machine, it was in reality a ...

Mercury felt the Pontiac GTO needed to be taken down a peg, so it built this to help in that endeavor.

There are some limitations when it comes to creating street-legal cars, but that hasn't stopped a lot of top car manufacturers from pushing the limits with racing engines. Whether it's a street ...