. "or a meaningful part of the proceeds of the loan are used to pay all or part of the customer's obligations to the seller or lessor under a consumer sale or lease, and if: (a) The lender is a person related to the seller or lessor; (b) The lender supplies to the seller or lessor, or the seller or lessor prepares, documents used to evidence the loan, other than sales slips or drafts used to evidence" . . . .