You can override some (not all, it seems) encrypted data* by creating a folder called 'data_override' in the extension folder and putting whatever edited X.ini you want in there, thus leaving the original data.acd effectively untouched and therefore not borking subsequent loading on cars that use encrypted data as part of their overall encryption. Normally, editing the data.acd or leaving it unpacked afterwards means that these cars will crash during loading.
So for what we're trying to do, the process should (I think!) be:
1. unpack the car's data.acd
2. copy the car.ini from the unpacked data folder
3. create a folder called 'data_override' in the 'extension' folder
4. put the car.ini copy in the 'data_override' folder (still call it car.ini, not car.ini_copy or whatever)
5. delete the unpacked data folder in the main car folder so that the original data.acd remains untouched
6. edit the car.ini that's in the 'data_override' folder with the commented HEADER and extended physics entries, keeping the rest of the car.ini config as the original
I've not tested this specifically for disabling extended physics, but it works for other stuff I've tried.
*technically, ALL data.acd is encrypted. I'm talking here about additional encryption that some modders use to lock down their oh-so-perfect creations.
