I added this to my server, gave myself permission for 8 rows in the camper. I open the inventory for the camper and it's still the default setting. What could I be doing wrong?

Do you own the vehicle? For example, did you spawn it via a plugin for yourself, or did you claim it via a plugin, or did you build the chassis via a plugin? If not, then the car probably doesn't have an owner (car modules don't have an owner either), so that's why the permission isn't applying. See the docs to learn more about how vehicle ownership works.

WhiteThunder

Do you own the vehicle? For example, did you spawn it via a plugin for yourself, or did you claim it via a plugin, or did you build the chassis via a plugin? If not, then the car probably doesn't have an owner (car modules don't have an owner either), so that's why the permission isn't applying. See the docs to learn more about how vehicle ownership works.

I put the vehicle together on a lift.

Assuming you mean you crafted the chassis via the Craft Car Chassis plugin, then make sure that plugin has the config option enabled to grant ownership.

"SetOwner": true

Wete you able to solve the issue with my above advice?

I never got around to revisiting this plugin.