> In practice, my number one use of a fob from a remote distance is locking, rather than unlocking, and those two operations don't have the equivalent security risk.

Yep, that's the simplest fix. Key is required in the door to open/unlock.

You'd think too that a firmware update to the car could enable that behavior. I mean most cars still have a physical lock on at least the driver's side door as a "back door" to getting into the car if the fob is non-operational.

The problem is that the overwhelming majority of cars are effectively abandonware on this metric.

This is exactly the benefit of the free software, and why having your own ability to fix, recompile and reinstall the software, is essential, even on things such as cars where you may think it's not needed or is too complex to handle.