(a) Security interest.--This subchapter does not prohibit the execution of an agreement between a buyer and seller whereby the seller retains a security interest in goods sold to the buyer until full payment has been made.
(b) Allocation.--Section 6329(b) (relating to add-on sales) governs goods sold under an agreement under subsection (a).
(c) Notes; third party rights.--An open-end credit agreement may not require or entail the execution of a note by the buyer that when separately negotiated will eliminate as to a third party a right of action or defense that the buyer may have against the seller.