I was just about to post on this subject myself....
The whole problem is that there is no collision checking between GVs, whether friendly or nme. The only way to stop the problem of jeeps driving inside tanks is to enable GV collisions, at least between nmes. Hopefully between friends, too, so we can have brutal crashes in GV races

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The ideal thing would be for jeeps to always die when they collide with ANY other GV, including another jeep, regardless of who "caused" the wreck. That way, tanks could run over jeeps, besides the jeeps dying when trying to drive "inside" tanks.
Might want to think hard about damage in other situations, however. It would suck if every tanker who lost his gun immediately set out to ram the nme, and could inflict damage that way when he "causes" the wreck. Also, we don't want planes kamikazing GVs all the time. But at the very least, nme GVs should not be able to drive through each other, whether they're jeeps or tanks. They should at least come to a stop: both GVs involved, regardless of who "caused" it.