Car rental...CDG or Orly?

Picking up from the Airport, you'll pay a convenience surcharge. You can't find a place in an outer Arrondissement to have a car ready for you? What about taking the train to Rouen and getting a car there? The train station surcharge is usually a third cheaper than the airport.

Probably easier to get to CDG on the RER "B" line than to Orly where you must make at least one change. And probably a little easier to take off from CDG toward Normandy without having to come around from the south. But you might look for a rental from the Porte Maillot on the west side of the city. Easy to reach by Metro, right on the Peripherique, quick escape toward Normandy. Or a location around La Defense, same advantages. These would avoid the airport surcharge.

CDG is better positioned for Normandy.

One of the reasons we like to pick up at airports is that they tend to have lots of cars and so you are more likely to get what you ordered or even a car at all. On two occasions, once in London and once in Rome we had trouble getting a car at all. In London, it was Christmas and people who were unable to rent cars (there is no public transport on the 25th 26th and we were visiting friends in Ipswich those days) rented them early and then just didn't return them so the agency had no cars. In Rome, the driver bringing the car around for us ran it into a light pole doing considerable damage; we had to take it damage and all or have no car. Airports have cars. Also we had to return our car in Caen during the long lunch break which meant no receipt on return which I don't like to do; we have in the past been billed for gas or for damage that we didn't incur.

But you can avoid the airport fee if you pick up on the northwest side of the city and there are probably agencies there.

My experience has been the same as Janet's: when going to Normandy, rent the car from CDG, because (this assumes you're also returning to CDG) it's easier to get to CDG when returning from the Normandy area.

I did what Bill suggested in the first post. By picking my car up in Versailles, I was able to save the airport surcharge. We took the train to Versailles and had to walk a few blocks to pick it up though. (with our luggage). Another thing we had to watch was the opening hours for the pick up place. City locations generally have much more limited hours (closing at 5 is common, although the one in Versailles stayed open until 7) Airport locations have much more generous hours. One other thing, both times I have rented a car in France, I have dropped it off at a different location and was not charged an additional fee for doing that. (In 2012, picked up in Lille, dropped off at Orly. In 2014, picked up at Versailles, and dropped off in Lille). So do not assume you have to return the car at the same place you rented it. The agent I worked with at autoeurope said that as long as I dropped it off in France, they don't charge the fee. I would double check this, of course, since each company may have its own rules. Autoeurope booked us with Europecar both times.