What is the test for a search of a vehicle in a motor vehicle search?

Appellant requested that the court instruct the jury with the following pinpoint instruction: "The police may only search the passenger compartment of a vehicle incident to a recent occupant's arrest only if it is reasonable to believe that the arrestee might have access to the vehicle at the time of the search or that the vehicle contains evidence of the offense of arrest. (Arizona v. Gant, supra, __U.S.__[129 S.Ct. 1710.)[] If you find that the police did not abide by these restrictions you may consider this failure as evidence reflecting on the credibility of the officer." Noting that Gant was decided after appellant's arrest, the court refused the instruction and stated that it was not relevant to the deputies' credibility "because there is no reason that they would have known that they were doing anything improper or illegal at the time they did it...."