I wouldn't mind seeing different year variations of models, for example, like having a new Kenworth W900, and have another, say a 1960's Kenworth W900. I think classic trucks would be a cool addition to the game, but even if the year gap between trucks is not that large, the game could maybe even feature a used vehicle offers, at a used dealer. You would have your new trucks of course - at the respectful truck dealership, but if you did not have that kind of money or something, flip through some different options for trucks that have been used, fix them up, and use them. It could be an alternative to taking out a large bank loan for a new truck, or could be the compromise you make to get more of your employees on the road.
I guess this post slowly turned into a wishlist post lol, I can move it if you want. The bottom line is it would be nice to see different year models of trucks.