Travel Rules of the Gendarmes

After carefully observing the gendarmerie of Paris for some days, I believe I have deduced the rules of how they are expected to move about:

1. Turn on the siren. This most important of rules applies to all but the most trivial situations. Being late for lunch is not trivial, especially in France.
   
   
2. Have many people in the car. Two is far too few. Five gendarmes looks more impressive to the people watching you whiz by with siren blaring.

3. Everyone in the car should look earnestly in the direction of travel. This rule must be especially important because I have never seen it broken. I expect this is to give the impression that where they are going is more important than where they are.
   
   
4. Never use one car when three, four or five will do. Convoys of cars, sirens blaring, many men in each car, all looking forwards with intense, earnest expressions. Egads! Whatever it is, it must be important. But why does it happen several times every hour?
   
   
5. As soon as you arrive at your destination, stand around and do nothing much. I deduce this rule from the fact that gendarmes are only seen in one of two states: either rushing about in cars, sirens blaring, or else standing about doing nothing much, often in impressively large groups (I guess that's why they need all the cars) and wearing piles of dark blue armor and armed to the hilt. As far as I'm aware, no one has ever observed them doing anything other than these two things.