Just tried it and yeah, something is definitely going weird. I haven't really done vehicle physics much before so I can't even tell if it's me or pandan. I'll keep toying with it and see if I can come up with a fix.
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Done. V2 is here! Hopefully this will work better. It may seem bumpier on terrain since I had to increase a couple settings about sixteen-fold and that means it will be a bit more sensitive to collisions. Oh well, it's better than sinking.