I've never heard of wrecks during WW2 being fought over as a point of monetary gain. Yes, granted, there was a lot of scrap to be had but by the end of the war we were seeing a situation where the US was literally dumping M4 Shermans into the ocean because they needed to get rid of them.

Once an area had been stabilized most of those wrecks would be pulled off the road so as to not block traffic, cleared of anything valuable (a radio set was quite pricey back then, and even then you had to consider that resources were so scarce that Soviet soldiers had a reputation for stripping the upholstery from wrecked tanks and vehicles because it made for good boots) and eventually disposed of. New designs were often shipped off to be examined and tested- while something like the 131 Tiger that still runs today was quite a prize in the fact that it was largely intact, often times even a wrecked hull was valuable in terms of metallurgical testing- and as for the rest it was largely a question of how easily it could be moved.

Vehicle and equipment wrecks weren't typically treated as, "Spoils." Folks may have wanted a slick German handgun enough that, "Soldier wanting a luger to send to his kid brother back home" is a Hollywood cliche, but you didn't really see situations where British high command and American high command got into a spat over who got to claim wrecks. Clearing them was a huge consumption of man power that'd otherwise be invested in important logistical details often, or represented boots not at or near the front.

Even post war you have to consider that most countries simply didn't want the chewed up remains. I know the French equipped a tank division with panthers after the war but they were not loathe to be free of them after a few years of service and could only comment that the gunner's optic was superb, but immediately had to take away that compliment because it was the only vision device the crewman had, meaning it was often difficult to line up his view with what the commander could see.

Of the scant few designs that remained in service post-war from Germany you're largely looking at things that weren't leftovers but rather productions that someone else assumed command of. The Spanish kept a number of German aircraft designs in service well after the war, but only because they were building them domestically. Yugoslavians were making what was essentially a clone of the MP40 well after the war as well. A fair amount of German equipment would, ironically, make it's way to Israel during their fight for independence over circumstances I still don't entirely understand.

But again, I can't say I've ever seen any documentation indicating a spat over who got to keep wreckage as a point of monetary gain. These things were eyesores and obstructions, not prizes.