Ok Dan, get you a tow strap. Remove the driveshaft, tie strap to car, tie other end to truck. Have someone drive you up to speed and see if the vibe is still there. If its still there continue to tow the car to the highest point possible and push it off(be sure to unhook from truck) LOL j/k.

I hate vibrations, my jeep is double the fun as it has two driveshafts with double cardan joints, so 6 u-joints and 2 slips yokes spinning at all times can be fun when you get a vibe.