Click or press space to see the other screenshots. I found out there's a Vehicle AI in the newer version of Rigs of Rods where you have the option do a drag race with other vehicles. Then, after selecting 2 vehicles and then clicking one of the presets and then clicking "start", it'll spawn the 2 vehicles. So yeah, that's how I did it.
P.S. I was just recording a video about this too. Couldn't get the finish line in it though, due to the 10 minute limit. I was 431. The other 1st Gen CEs were 432 and 442, but the city buses didn’t have numbers from what I’ve seen.