Ben where are you from?
If you are from Antartica then no .... or even Equaltorial Giunea.

However NSW Australia you would yes.....
Harnesses would need to be bolted to existing seat belt mounting you would use for for rear passengers. This means you would delete the rear passenger seat in a coupe for instance. If they were bolted to the rear parcel shelf like in a sedan again the rear passengers would be deleted...you would have to think why you would nee harnesses in a street car apart from sheer wank factor.