Convertibles and Wrangler Doors could be manufacturer - Just like some states allow no rear bumper on Trucks as they can be a dealer option to be installed.So.... how do they handle people taking the top and doors off their Wrangler?
Now you're trapped. Grab some bacon and feed it to @Xue Sheng.
It also could be Airbag or other safety device related.
I just know that NY has different / more stringent requirements for state certifications.
Or they did a few (5-10) years ago last I checked.