1. A lender shall not contract for or receive a finance charge exceeding twenty-one percent per year on the unpaid balance of the amount financed for a loan of money secured by a certificate of title to a motor vehicle used for personal, family, or household purpose except as authorized under chapter 536 or 536A. A consumer who is charged a finance charge in excess of the limitation in this section may seek any remedies available pursuant to this chapter for an excess charge.
 2. It shall be a violation of this section and an unlawful practice under section 714.16 to attempt to avoid application of this section by structuring a loan of money secured by a certificate of title to a motor vehicle as a sale, sale and repurchase, sale and lease, pawn, rental purchase, lease, or other type of transaction with the intent to avoid application of this section or any other applicable provision of this chapter.