paulkish
old fart
How about putting an V or L or \_ shaped thing mounted to pivot and mounted to the outside of or underneath the LR chassis rail behind the LR tire. The top of it would be weighted and it would be held in a non operating position by a light adjustable spring. Centrifugal force would make the weight move and the other end would move down and dig into the track, holding the back end in. ... 
cool Idea huh? ya want to keep grip at the LR, stick something extra down on the track to do it.

cool Idea huh? ya want to keep grip at the LR, stick something extra down on the track to do it.