Rent car in Marais, drop off at CDG?

Not clear. Is it that you want to find a car rental in the Marais in Paris and drive to Normandy and Brittany and drop it off at the airport?

Correct. Rent the car near our apartment in the Marais, leave Paris that day, do a big loop and return it at the airport on our way out.

Avis has 4 or 5 offices in Paris short ride away from Marais
https://www.avis.com/en/locations/fr/paris

Europacar in the Marais
27 Rue du Grenier-Saint-Lazare, 75008 Paris, France

https://www.europcar.fr/

Perhaps train to Brittany (Rennes??) and pick up your car there. This would mean just a one way drive back thru Normandy to CDG.

There's no charm in driving in central Paris.

The trip to Normandy and Brittany is so short that you might as well save parking fees, toll fees, gas charges and just take the train to the first city you'd like to visit.

Pre-book a car at the station in the first city where you'd like to be.

Take the train back to Paris, where you will not benefit from trying to circle the block thousands of times, paying outrageous garage fees, paying parking tickets, etc.

If you don't have lots of luggage, you can take the RoissyBus to the airport, using Metro/RER.
Otherwise, take a taxi with fixed rates for 55 EU to the airport.

I agree with chexbres about taking the train. You could pick the car up in Caen and then drop it at CDG, as you planned. The Marais can be frustrating due to very narrow one-way streets and trucks blocking streets during deliveries. You could waste a lot of time.

If you still want to pick up in Paris, rental agencies in the Gare du Nord are close to you, Gare de l'Est is a few meters closer but smaller, or the Gare de Lyon, but that one is east of you and you're driving west out of the city. Some people take the RER out to La Defense to get their cars and drive from there. I don't think there are car agencies in the Marais--the one posted above is close to the Champs Elysee.

If you look on autoeurope.com you'll see all your possibilities. Autoeurope contracts with many different rental companies.

Thanks--we will be hitting a couple of brief stops on the way to Normandy, so a train isn't really an option. Appreciate it!

There are rental agencies at Gare de l'Est. I'd use this station instead of Gare du Nord, which is a madhouse.
When you come back to the Marais, you had better check out parking garages and hope that they have room. It's impossible to park on the street in most of the area - especially when some streets are closed during the weekends.

We loved driving driving through Loire Valley, Brittany, and Normandy. It was very relaxing for us to drive through these regions. Such beautiful towns.& country. The only challenge we had was that the fuel trucks went on strike one of the days we were traveling & it was challenging to find a gas station that had gas. We knew the strike was going on and checked every opportunity, so we were ok. However, I would NOT choose to drop the car off at CDG. It is a very huge, complex airport. We made that mistake.

Oh the horrors of driving in downtown Paris! I would recommend taking the train as far out of Paris as possible and then renting the car from there.

We've returned to CDG many times and it is a huge, complex airport with many access points, switches, etc, but doable. A GPS wouldn't hurt.

We rented a car from the Avis location near the Opera. We then dropped it off a CDG airport a week later. Luckily the car had GPS which helped get us out of Paris. It was a bit tense at first, but then it was nice to have a car to stop wherever we wanted. Normandy and Brittany are both beautiful. Have a wonderful trip.

I'd agree with the recommendation to get out of Paris before you rent your car. Plan to pick it up at wherever your first stop is. You will save time not messing with traffic getting from the Marais to the west edge of Paris.

When I was shopping for my car, I was also surprised to find limited options that allowed me to pick up and drop off where I wanted. I checked lots of places and eventually found something that worked. One reason is many of the smaller town rental agencies will have a long lunch break in their hours (maybe 1130 to 1430). If you enter a noon pickup or drop, the search will show very limited options. CDG will be open all the time.

Bill, Your plan is reasonable.
We've driven into and/or out of Paris on 5 previous vacations and are planning to do so again this summer. Clearly, most people think driving in Paris is to be avoided at all costs. I disagree.
We have always found a parking place near where we're staying. It may require a few trips around the block, but sometimes we've found a convenient place on the first approach. No fines, no parking garages fees. I'm thinking this will be good for you to know if you pick up the car, then go back to load your luggage.
It's also possible to rent from a neighborhood site and drop off at the airport. Shouldn't be a problem once you locate a rental office near you in the Marais. I don't know, but maybe you should be looking at European agencies like EuropeCar, Autoeurope, sixt, etc. instead of names like AVIS.
FWIW we make arrangements through Gemut.com. If you're still having problems, maybe they can help.
Bob

I agree with the majority of posters that driving in Paris is to be avoided if possible. The best solution would be to take the TGV to Rennes, rent a car at the Rennes train station, and do Brittany first and then Normandy on your way back to CDG. If you are already locked into doing Normandy first, I'd find a rental location on the outskirts, such as La Defense, rather than a train station in the city center such as Gare de l'Est.

I agree with those who say to avoid driving in Paris. But if you want to do that, renting a car in the city and returning it to CDG should be no problem. Half of my French rentals have involved returning the car to a different place from where I picked it up, often involving a return to CDG..

FYI, we're not coming back to the Marais--we'd be picking the car up after we check out of the hotel in Paris and hit the road to Giverny, etc. However, there was a comment that scared me about returning the car to CDG, which was our plan. We are spending our last night close to the airport, in Roissy-en-France. Would there be a better way to get the car returned in advance? Or is that not worth two trips to the airport?

We returned a car to CDG after staying in a hotel near the airport and had a lot of trouble finding the car rental return. Took us about 45 minutes of going in circles. I think we were on the back side of the airport. We found our way eventually. Just make sure to allow plenty of time.

When we returned our car to CDG last year, traffic was insane, but we didn't have any trouble finding the return location. But you really do have to keep your eye out for the signs.