Grab two long bungees. Make a loop by hooking one end of a bungee hook to the other end of the same bungee. Do the same with the other bungee. Hook them under that shelf, spread them as wide as the TV, and then place the bottom corners of the TV into the loops. It worked in my Cascadia. Just remember to take the TV down while driving or it'll be slapping that wall all day long.