Wis. Stat. § 402.209
Not every contract for the sale of goods over $500, nor every modification thereof, strictly complies with the requirements of the statute of frauds, and it would be unreasonable to declare categorically all such contracts unenforceable. The UCC and Wisconsin case law recognize exceptions to the statute of frauds, including waiver and performance. An attempt at modification contemplates a completed oral modification of a written contract that prohibits oral modification. The inquiry into whether there has been an attempt at modification sufficient to operate as a waiver of the statute of frauds is closely related to the inquiry to determine whether there was a valid oral modification. Royster-Clark, Inc. v. Olsen's Mill, Inc., 2006 WI 46, 290 Wis. 2d 264, 714 N.W.2d 530, 03-1534. A dealership agreement is primarily for the sale of goods, making this section applicable. American Suzuki Motor Corp. v. Bill Kummer, Inc., 65 F.3d 1381 (1995).