Hi. As I remember on some of the PE sheets for certain German vehicles, there are pieces for such coverings provided, and these being metal, I would assume that the original ones on the real vehicles were as well. And I have seen photos of these items placed on models without the tools in them. So I would say, from my point of view anyway, the other poster here is correct, and just paint them the same color as the vehicle.
Take care, sgirty