The Empi Sportster came out of Southern California in 1963, as a "Build your own Dune Buggy" kit. They were available as a pre-fab kit. or you could order the plans for $9.95, and build it from scratch.

Most of these, with the acception of a few, were built on 12" - 14" shortened Chassis. The few built on full length pans were usually 4 seaters, opposed to 2 seaters. Pictured below is a sportster on a full length pan, but still a 2 seater.