That's What I Thought Too, But Called One On Sun. And She Confirmed It Meant Car Date For Her...

so maybe not definition worthy yet, but it was definitely new to me.

The ad I called is down now, guess we'll see if it reappears...

But first you take a number. Then you need the board to light up when your number gets called...comes up....whatever.....maybe there will be benches nearby to sit and wait on...of course YMMV

Here are some ideas:

 1) Put a "take a number" dispenser on the side
 2) Put a bullhorn speaker on the roof, and call each number in order
 3) Use a "now serving" number message board on the side
 4) Put your website URL on the side?
 5) Put a small sink/toilet in the van
 6) How about a grill, and serve food too?
 7) On the external speaker, play sexy music?  Bolero for example?

But the interesting idea would be to section the front seat off from the rest, and have someone drive around while "fun" happens in the back.  Might make it more fun.  

A real interesting idea would be to put large picture windows in the back, but make them one-way glass so you can see out, but nobody can see in.  That would be cool to be getting some satisfaction and see everybody else, but noone can see you.   The other is to flip the glass so the customers do not know they are being watched, but you know.  This would be good if you are exhibitionist???

Boy, I have too much time on my hands.

Re: Okay I am kicking myself now.....

Rea next time your in Vegas we'll try it.