I was in my '50 Buick, cruising down a 2 lane street today, doing about 35-40mph, when my rear wheels locked up tight! I was able to maneuver the car to the side (bicycle lane). I hopped out and popped the hood half expecting to see smoke, steam, oil... Everything looked great, so I thought my trans might have seized or something. I looked down at it and realized the link pin that holds the shift linkage was gone. I walked back 20' and picked it up, grabbed a cotter pin, put everything back together (burning my hand on the hot exhaust in the process) and continued on my merry way.

The trans had shifted from drive to reverse. I'm glad this didn't happen on the expressway...