Vehicle handling and meta can be handled in multiple places/by many different factors (electric vehicles, motorcycles, boats, etc shouldn’t be edited with the same methodology as cars) you may also have some addon vehicles that replace those handling files.
I’ve seen quite a few addon cars (usually intended for single-player) that will stream (is that the right word?) replacement meta files for said vehicles.
We’d need to see the exact meta files you’re editing/replacing/streaming and some info in them to assist you further.
Additionally, it may be easier to just load a “replacement” for all vehicles and edit those individually rather than go through and try to make your own.
This is intended to remove weapons from vehicles but is a good base to start from as they stream all the vehicles I think.