Those seats are another reason to be pulled over. The seats are legal in the Brat (OEM equipment) but the state of CT requires an insurance rider to be carried by the car while in operation (Not necessarily while just in use, but while they are installed). Without that rider, you get the same charge and procedure for driving with no insurance / insufficient insurance.
The rider is typically $600 +/- a year added to your insurance coverage. Totally not worth it.
If I recall correctly, the seats in the back of the Brat were there simply to allow Subaru to import it as a passenger car rather than a small truck, saving a whole lot of taxes (or possibly having something to do with emissions or mileage standards). They were simple to remove and almost everybody did.