Some motorsports series have never had the pretense of having any relation to production cars, but two of the biggest ones in the United States, NASCAR and NHRA, had their origins in "stock" car racing, with at least nominally production-based models duking it out at the quarter-mile or oval track. Over time, these cars evolve into cars that can barely be considered street-legal or in any way "stock." Hot Rod has worked to keep the grass-roots spirit alive by introducing successive series requiring competitors to use publicly-available pump gas, and most recently with Hot Rod Drag Week, bringing their own spare parts and supplies on-board their vehicle between races, or towed by the car on a trailer.
Once again, the competitive spirit is stretching the definition of "street car" with fiberglass-body and tube-frame vehicles competing in Drag Week. But Freiburger says so far, the process of natural selection has weeded out the weaker specimens, leaving only the strongest of the breed that can reliably traverse the thousands of highway miles driven during Hot Rod Drag Week, plus full-throttle runs down the track at each event. Freiburger says the rules may change in 2014, but that Drag Week rules have been left deliberately liberal to allow for a wide variety of competitors to prove themselves on the street and the track during Drag Week.