Strange, not too sure what it could be then as everything in your XMLs seem fine. The only other thing I could think of is that you might have a carcols.meta or carvariations.meta in update.rpf\dlc_patch\*yourDLC* that's being loaded over the one you're editing with bad values?
There's no file in update.rpf\dlc_patch\
Strange indeed. I went over the .metas a thousand times already, can't find anything.