If you are going to rent a car in Paris and travel to Normandy and then to Alsace-Lorraine is it best to rent it in Paris at CDG airport and return it there or return it in Alsace-Lorraine and take a traine to Paris? Any idea of the tolls?
Are you staying in paris? If not, rent in CDG the drive to Normandy, then to Alsace, drop it and take the train to Paris. If starting your trip for several days in Paris, either get the car on your way out, or train it to Normandy, then pick up your car there. Don't sit on a car if you're going to be in paris for several days. Driving/parking is Paris isn't fun.