Modified racing began as race drivers modified their cars to gain a competitive advantage over their fellow competitors. What started out as minor modifications to the cars has now grown to the point that some modified classes are no longer based on any current production vehicles. NASCAR was instrumental in modified racing's beginnings. Some of NASCAR's pioneers were veteran modified racers long before NASCAR's inception in 1949. As time progressed, modifieds grew away from "strictly stock" or "stock cars", and became akin to both stock cars, and open-wheel cars. Today's supermodifieds have more in common with Indy cars than they do stock cars.