Conn. Gen. Stat. § 14-29a: Registration of motor vehicles over ten years old as taxicabs prohibited.

No motor vehicle that is engaged in taxicab service shall be registered by the commissioner if such motor vehicle is older than ten model years old. Notwithstanding any regulation adopted pursuant to section 13b-96, any such motor vehicle that is validly registered and will be older than ten model years old during such registration period may continue taxicab service until the expiration date of its current registration, after which such registration shall not be renewed.