In 1970s Ontario, California, Matador Motor Co. chased the GT40 dream with a compact, home-build coupé called the Matador GT. You could even buy it finished: a turnkey car hovered around $3,300, leaving you to choose only the extras—glass or Plexiglas window sets, an interior trim package, and a lineup of magnesium wheels that gave the little GT its stance.Most enthusiasts, though, came for the kits. The entry path was a budget $795 bundle…