C.R.S. § 42-4-1807

The lien provided for in section 42-4-1806 shall be perfected by taking physical possession of the motor vehicle and its attached accessories or equipment and by sending to the department within ten working days after the time possession was taken a notice containing the information required in the report to be made under the provisions of section 42-4-1804 . In addition, such report shall contain a declaration by the operator that a possessory lien is claimed for all past, present, and future charges, up to the date of redemption, and that the lien is enforceable and may be foreclosed pursuant to the provisions of this part 18.