I mean.. that's why I'd love some legal professionals to jump in...

I'm just quoting the literal modern law which has obviously dealt with this loophole

A person appropriating property belonging to another without meaning the other permanently to lose the thing itself is nevertheless to be regarded as having the intention of permanently depriving the other of it if his intention is to treat the thing as his own to dispose of regardless of the other's rights ; and a borrowing or lending of it may amount to so treating it if, but only if, the borrowing or lending is for a period and in circumstances making it equivalent to an outright taking or disposal.

It happens that there is already a separate specific law for vehicles so that applies to vehicles. The clarification applies to other stuff to stop people using the same excuse and getting away with theft without a separate law for every single other type of item...does that make sense?