What are the elements of possession with intent to distribute a controlled substance?

Appellant was convicted of possession with the intent to distribute a controlled substance. 21 U.S.C. 841(a)(1). The elements of this crime are (1) knowingly (2) possessing the substance (3) with the intent to distribute. United States v. Davila-Escovedo, 36 F.3d 840, 843 (9th Cir.1994) (citations omitted), cert. denied, --- U.S. ----, 115 S.Ct. 953, 130 L.Ed.2d 896 (1995). The parties agree that the only element at issue is the knowledge predicate; thus, the issue on appeal is whether the jury plainly erred in concluding that Appellant knew that drugs were in the vehicle.