Those cars are inspected and cleaned after each rental. He was also kicked out of the Service for cocaine abuse.
True story:
I was driving to Houston almost every weekend from Abilene (Dyess AFB) to Houston (Girlfriend), I racked up so many speeding tickets DPS took me to Court. I showed up spit polished in my Blues w/Ribbons and got out of that, but the Base Police yanked my driving privileges, so someone else always had to drive my car on base. We were coming through the Housing gate one night after drinking in Buffalo Gap (Abilene was Dry) and they stopped us and searched the car, lo and behold they found a pipe with marijuana residue hidden, it wasn't mine! but I got the Article 15 anyway and took it like a man, never found out whose pipe it was.