When I was a kid, we drove up Pikes Peak, CO. Back then most of the road was gravel and there would be 2-3 brake check stops on the way down. But, heading up I remember seeing all these crosses dedicated to folks that went over the edge and yes, I wondered what they did with the cars because most those drops were steep slopes that just kept going and going. That was back in the mid-70s. Never recalled seeing a car though.