It was a rental car, it couldn't have been in there too long. Unless Enterprise is offering new services. I'm not saying it's impossible or even improbable that he was high at the time, but the mere presence far from guarantees it. He had a lot of weed in there, doesn't it follow from everyone's logic that he must be smoking all of it on that car ride. He may have smoked it earlier in the night, he may have not wanted to keep it around his hotel/apartment, he may have just got it from somebody at Shannon's. I'm not even one to say wait until everything is proven before assuming things, as I assumed he was drunk as soon as I heard the accident repot, but I'm not convinced he was high.