An addition - I didn't want to drill a hole in the apron of my 66 K Fastback for the forward Monte Carlo Bar bolt. I get around this, I took a 5/16-18 "T" nut (the type used in woodworking), bent the three retainer barbs flat, trimmed the threaded portion to be less than the thickness of the Monte Carlo Bar's mounting plate (Dremel tool), shortened a 5/16-18 bolt to 3/16 thread length and installed those kluges to the bar at each end. A piece of tape between the apron and the "T" nut keeps the scratches to a minimum. The bolt/nut are there for looks, the bar comes off for show, without an extra hole in the fender apron. I don't race the car, the bar is there for extra support.
Jim