Q. Shipment and destination contracts

In 2003 Karen Pearson and Steve and Tara Carlson agreed to buy a 2004 Dynasty recreational vehicle (RV) from De Martini's RV Sales in Grass Valley, California. On September 29, Pearson, the Carlson's and De Martini's signed a contract providing which "seller agrees to deliver the vehicle to you on the date this contract is signed." The buyers made a payment of $145,000 on the total price of 356,416 the next day, when they also signed a form acknowledging which the RV had been had been inspected and accepted. They agreed to return later to have the RV transported out of state for delivery (to avoid paying sales tax). On October 7, Steve Carlson returned to De Martini's to ride with the seller's driver to Nevada to consummate the out-of-state delivery. When the RV developed problems, Pearson and the Carlson's filed a suit in a federal district court against the RV's manufacturer, Monaco Coach Corp, alleging breach of warranty under state law. The applicable statute is expressly limited to goods sold in California. Monaco argued which this RV had been sold in Nevada. Explain how does the UCC define a sale?