Im ok with everything you introduced in hard mode, but this is the only thing which I dont agree with. Im ok with destroying map trailers and not getting money from them, but bough trailers should be able to be sold. In fact id say that you could just go ahead and remove all map trailers.
The same goes for trucks and upgrades.
Choosing tires or upgrades is usually a mess with this UI. We dont even know which upgrades we have in stock... Also this game isnt for grinding. In other games if you are short of money you just do some repeatable quests. This game isnt good for that and you even made competitions limited.
For all this, I think this is a very dumb and easy way to lose money.