Making the empire specific buggies immune to mines could be a start then? Immune as in not setting them off, at least. It makes sense from the Thresher point of view anyway.
I was thinking of the same thing for ATVs as well, but with ATVs down to 1 cert point I've seen plenty of them kicking around (though I haven't seen many people following me in running Fury raids against BFRs, and hunting down wounded tanks as they pull back for repairs. It would be nice if ATVs had to be closer to mines to set them off though.
EDIT: BTW, the Marauder makes the perfect anti-BFR tool when given a chance. You've got enough speed to get around the back of the BFR, a 12mm to knock out its shield gen, and a nice Ground Pounder to finish the job. The trouble is, any mines near that BFR and you're toast, a flight variant will just fly off if it gets into trouble, and a gunner variant with any half decent gunner can toast you even if you are behind it.