Many years back, for our Model Railway Club annual exhibition, we cannibalised a section of an old layout for a window display in a local shop. A GWR railcar ran across a viaduct, and off stage, then ran back again. This set up ran 16 hours a day 7 days a week for three weeks. Each day I changed the railcar (we had two) and serviced the other. No bother with turning around, both railcars were double ended. An electronic counter kept a tally of the number of "trips" and after the exhibition I sold them both. "Mint condition, carefully run in, regularly serviced, only 44 miles on the clock."