It's a convertible, so it's a Super Beetle which, like Travis said, uses a longer cable than a Beetle. Also, if I remember correctly from when I worked on Joy's 75 convertible's speedometer, the Fuel Injected cars had some sort of box the cable fastened into, and a short cable that connected the box to the speedometer. The 71/72 Supers had a flat windshield so they may or may not use the same cable as a Beetle . . . in other words, even if the cable you got was for a Super Beetle, there might have been as many as 3 different lenghts. If the cable is too short, it might still reach from the wheel to the speedometer, but it could be in a bind causing the jumping. Most likely, however, it just needs lubricating or the square end of the cable is slipping in the hole in the dust cap at the hub.
