for people who cant afford the game and want to try the game in the tech-demo should know the you can switch vehicles and edit their vehicle.
i kinda like this actually. but they should only have the pickup(or whatever vehicle is in the tech demo now) with some configs, so people can see its possibilities.
You could maybe have just two vehicles to demonstrate the vehicle selector with only one config. To demonstrate the selector and to see how many cars they can run on their pc.
what else would it be there for? Its an advertised feature you can change the vehicle in the full game or run multiple vehicles, plus configure and tune them. The demo literally exists as a taste only. Can;t afford it, thats sadly your problem not the developers.
I think that would be a good idea, but they should add a physics prop.. object.. thing to it and let them have both spawned at once, to just get to know the game a bit better.