Hi, just got the game and its really chill, I love the atmosphere !
Id suggest some (skippable) animation when arriving to a seller, like the elevator going down, doors closing and having your tank in some sort of garage where you could refuel with a jerrican, maybe where you could repair your tracks and add features. Speaking of features maybe we could choose wheels, less tractions but less bouncy, as someone else said a crane rather than the arm that would make loading and unloading easier but would be harder to collect parts.
I also think some enemies would ne required like other scavengers but bad guy and we would have to defend ourselves with a mchinegun or maybe by tearing apart their rig, and also maybe with some wildlife like polar bear that would required to be afraid with flares, flares that could be used at night to light your path on the frozen lake !
You have done a really good work so far and you could really make a great game with some lore, more NPC, more structure like bigger ships you could explore, towns etc... good luck guys !