Okay, here's a hint: EMF increases logarithmically the closer you get to the source of the EMF. The tapes didn't sit over the spark plugs in my car which, themselves, are shielded in a large engine block. If, however, they road the conveyor, they'd be right on top of the unshielded motor that drives it.

You weren't "taking me at my word," because I didn't say, "motors damage tapes." That's a gross and inaccurate (some might even say, "stupid") over-simplification.