Mirror tint is illegal in NJ and most other states. You wouldn't have this problem if you just got your car tinted legally. No quality tint shop will put illegal tint on a customer car. You should tell the cop the name of the shop that put the tint on your car so they get fined.

NJ Window Tint Laws

Visor.................None

Front doors.............None

Rear doors................Any

Back window............Any