I tested mine with a trailer and it does work, however, the part count on just the truck alone is 200+ and with the trailer, even my gaming laptop struggles to cope. In the latest version, i did add the lights and everything, and as i predicted with the sloped roof, it has pretty good downforce. 2 pairs of wheels in the front really help with turning. I just need to tweak it some more and it will be good to race.