SpongeBob and Patrick accidentally destroy Squidward's house during a heated battle with Man Ray. SpongeBob promises to pay Squidward for the damage and agrees to sell "his vehicle" to Squidward at a substantially reduced price in lieu of full payment of his debt to Squidward. In the written contract, however, SpongeBob neglected to specify which of his two vehicles he agrees to sell to Squidward - the sand tank or the unicycle. If this case is litigated, would the parol evidence rule allow introduction of evidence of the specific vehicle to be sold? Why or why not?