Ind. Code § 9-32-13-5

Sec. 5. It is an unfair practice for a dealer to willingly fail to perform the fiduciary duty imposed on the dealer by IC 6-2.5-2-1 with regard to the collection and remittance of the state gross retail tax. Willful violation of the fiduciary duty includes written or oral agreements between a dealer and a prospective purchaser that would give the appearance that a bona fide trade-in has taken place, when in fact the purpose of the agreement is to reduce the prospective purchaser's state gross retail tax and thereby deprive the state of revenue.