Vt. Stat. tit. 23 § 1253
Permits issued by the Commissioner in accordance with the provisions of sections 1251 and 1252 of this title shall be carried in some easily accessible place in the vehicles authorized to use the equipment and shall be available for inspection at any or all times by any law enforcement officer, or during the inspection by the authorized personnel of an official inspection station designated as such by the Department of Motor Vehicles, as provided by section 1222 of this title. No inspection sticker may be issued for a vehicle equipped with a siren or colored signal lamp, or both, unless a current or valid permit for the siren or colored signal lamp, or both, is produced for inspection. If a vehicle's permit is issued pursuant to subdivision 1252(a)(5) of this title, a copy of the permit is acceptable.
23 V.S.A. § 1253