This semi is looking great! Make it a tad more boxy around the front fenders and the hood and you got yourself a good ol' 1980's semi...
Ensure your origins are set to 0,0,0 else this happens. Think you have to reset transformations or something in blender?
the semi would look more quality made, going to the extent to make your own wheels, I wouldn't mind waiting longer for you to craft new wheels for it.
Cool, perhaps the front tires could have slots instead of round holes like a farm truck steel wheels? its up to you, I don't really want to have to compare the semi and the T75 by going "well, it has the same wheels and tires"
That will look great, have you thought of a name for it? I think maybe the semi (model, not the brand) ​Maxum...
Update: Fixed mesh moving around, thanks joeyfuller got the color selector to work on the truck textured the front gaurd
you should add bunk-beds in the back area of the truck (so the truck driver can sleep) also mudflaps might be nice