RE: Are deer scared of cars?
Yes the deer would be and are nervous about his truck being that close.
The reason that guy likes to park there is because he knows that every time he's keeping the deer away from you.
Think about it every time he pulls in to park he revs up his engine slams the door and makes all kinds of noise very loudly.
The fumes from his truck will linger around your hunting area for a couple of hours and if you see any deer at all, then consider yourself lucky.
If I were you, I would move my stand and get far away as possible from that jerk.