There is an air filter on these trucks? Where is it?
I have the same trouble with a light plane in a hangar with a concrete floor.
What I did to keep them out is to get some thin sheet metal, like 30 ga. One piece for each wheel. Have it cut long enough so you can bend it in a rectangle and place it around each tire. It will have to be tall enough so the mice cannot jump over it, but of course must fit under the bottom
of the fender. This makes a un- climable barrier for mice around the only part of the truck touching the ground.

If it is sitting on dirt or grass, it probably won't work- they'll dig under the metal.

Where is that filter?