I lost my rear u joint one morning going to work(late again) on the rich/san rafael bridge. Speedo said 95 when I looked down and the gear shift was vibrating wildly. Let off the gas and it sounded like a shotgun went off underneath the car. Looked in the rearveiw mirror and saw my driveshaft doing the bouncy bounce behind me. Must have really freaked out that vw bug that ran over it. Wasted both mufflers and I had to find a new driveshaft. THAT sucked. Still no loop. I learn the hard way.