Our daughter did sometime in DC last year. Her office was across the street from the Capitol building, so she saw a lot of motorcades coming and going over the months. Once when we were together I showed her a video of this set up from Dillon. She said it explained a lot of what she saw. Almost all the Suburbans in the motorcades have some type of hatches in the roofs. Would be fun to see how they all are set up.
On a similar note, I was in the Twin Cities when President Bush spoke there a while back. Have you ever seen a Suburban going down the road at 60 +/- with two guys sitting on the tailgate with legs hanging off, and all the passenger doors open with one foot inside and the other on the running board? I lost count of how many there were around the three black limos as they sped down 35W from downtown to the airport.