If he drives over with someone else outside the limo, they’ll probably let him in. In the limo they’ll probably check everyone’s ID and background. In a car, your holding up the line and they’ll just waive you through without really doing a background check.
A friend of mine hasn’t been denied yet doing it this way. Just have him say he’s going to the Casino. They like to see money going into their local economy.
EDIT: And the worse they will do is turn him away. Its not like he’ll get the chair or something.