OK, so I wasn't on the bike at the time. It happened like this: coming home from a ride out east of town, cruising up I84 at 75. Halfway zoned out, and I hear <pop!> <creak> <thud>, and look into my rearview to see my brand new Anthem cartwheeling down the fast lane, still locked into my forkmount bike tray. It took a good ten seconds to process that that had, in fact, happened, before I started swearing as load as I could and looking for someplace to pull over. Walked back down the interstate in my flipflops. About halfway back, a silver WRX has pulled over, and the girl in the passenger seat rolls down the window as I walk by: "You lose a bike?". A few hundred yards back, the driver has my bike (tray still attached) over his shoulder, and I hustle back to him. It was lying in the middle of the freeway, and he said it almost got run over at least a couple times while he was trying to get to it to pull it off the road. I don't know how he did it without getting hit himself, but he has my enternal gratitude.
Anyway, I thanked him and hoofed it back to my car to inspect the damage. My car uses Thule "aero bars", which require you to secure everything to a little bolt the fits into a track in the bars. That bolt just snapped, letting the bike pull up and back and bending the aluminum tray out of the plate securing it to the rear crossbar. The jaws of the tray took most of the damage, I think - a few ounces of metal shaved off, and at some point the lock cylinder gave up and let the jaws open. A half inch of the left pedal (crank bros candies) is ground off, ditto the rear quick release. Front brake bled to death on the ride home in the trunk. Saddle has a good chunk missing, and the front fork is a little flatter and shinier than it used to be in one spot. The rear triangle and/or linkage may be bent a little too, but the lbs guys weren't sure, and weren't sure how much it would matter if it was.
Anybody else ever have something like that happen? The local rack dealer said he's never quite trusted the aero bar setup, and showed me some Rocky mounts stuff that looks a hell of a lot beefier. I'm just gonna trunk everything for now, but what do you all use?