At the Corn Carnival.
I guess they ran the cars in reverse?
Yes they did race model T in reverse. My dad, born in 1901 told me that he race a model T in his days and they turned the axle over to the other side, so the car now had two speeds in reverse.
If you're reading this Tom, then you're remembering a certain backing up race at Greenfield Village some years ago aren't you?