Tax is a lien against vehicle -- Removable only when tax is paid.

Utah Code § 59-13-311, under Part 59-13-3: Special Fuel.

Utah Code § 59-13-311

59-13-311. Tax is a lien against vehicle -- Removable only when tax is paid.

The special fuel tax constitutes a lien upon, and has the effect of an execution duly levied against, any vehicle in which special fuel is used. The lien may not be removed until the special fuel tax is paid or the vehicle subject to the lien is sold in payment of the tax.