No, the 'factory-approved' rear electric antennas that were directly mounted on the top of the rear fenders (both Jr. and Sr. Models) had a spacer (insulator) - though NOT the same as used for front fender mounting - that went between the antenna dome nut and fender. This particular spacer was not only contoured to match the crown of the rear fender, but also gave the antenna the desired angle. It did sit atop a pad/grommet (seal).