going to Paris in July. Will then go to Normandy Dday beaches, Mt. St Michel etc. Right now going via train to Normandy area, as I do not know how to drive stick shift. How reliable is it to reserve automatic in Paris (from the USA) and then travel to Normandy area, I have heard sometimes they do not have the cars or you need to reserve months in advance. Do not want to risk this as it can "spoil" the vacation.
Automatics are rare. You'll pay extra if you can even find one.
You'll get a car if you reserve it today for tomorrow. I you reserve a year in advance, you might be promised an automatic. What they'll have when you get there is a different story. Bayeux has one small rental joint. Caen, two or three, but they're also small. Many sites will not show cars available if you specify automatic, but have any number available if you don't. Your odds are much better, but I've seen people in front of me wringing their hands, if you pick up from Nord or one of the airports. My standing offer is that, starting from Nord, I can drive and beat anybody taking the train to Bayeux. With both starting from Roissy, I've got time for a sandwich along the way and a cup of coffee waiting around in Bayeux.
If you reserve a year in advance, you might be promised an automatic. What they'll have when you get there is a different story. Reminds me of a classic 'Seinfeld' scene - the car reservation scene: http://youtu.be/4T2GmGSNvaM