I saw a Bachman trolley kit that ran on a single line. It would stop at each end and then change direction. Perfect way to ad a line in my layout where there is no room for any way to turn around. The issue is that I do not want to buy their kit because 1. I do not need more track, 2. I do not use EZ track, 3. I did not like the trolley in the kit. How can I do the same thing using my flex track with a trolley or engine of my choice? Just an FYI I would be using flex track.