We are planning to leave Paris and go to Chartres then to Loire valley for 3 days. I would like to rent a car so can see Chartres on the way and drive to the different chateaux. Problem is we fly out Tuesday afternoon - should we drive to the airport to pick up our car so we pick up/drop off same place? Should we pick up somewhere in Paris and drop off in Loire and train to airport? Is there fees to drop off at different locations?
So many different scenarios not sure which make sense.
We took the train to Chartres (about 10euro each) and then picked up a car there. We rented from Autoeurope and the car was provided by Hertz. We returned the car in Tours and took the high speed train back to Paris. There was no drop charge, but that is something you should double check.
We've done similar to the PP - train to the first stop, pick up the rental, then dropped it at the agency at the St Pierre des Corps station in Tours before taking the TGV back to Paris. We used Sixt, and had no drop fees.
There are not usually drop charges for different cities within France. There may be small fees for an airport or train station, but that's pretty much a necessary evil. My first instinct also would be to pick up the car in Chartres. Train from Gare Montparnasse is a bit faster than picking up a car near the station and driving the same route (although it is a pretty straight route).
A few times per day, direct TGV trains do go all the way from St-Pierre-des-Corps to Aeroport Charles de Gaulle TGV station. Buy these fast-train tickets in advance for a discount.
You can avoid the typical 40€ train station/airport location surcharge by picking up a car in Paris. If you are going to Chartres, there are a number of rental locations in the 13th or 14th which would give you easy access to Port d´Orléans and A6 from which you will take A10 and then A11 to Chartres. You´ll also avoid the unnecessary costs of train tickets and probably have a greater selection of rental cars.
Check with either Six or Europcar as they typically do not charge one way, in France drop off fees. Hertz and Avis will reliably charge you which is why I might avoid them. In any event, you should check with Autoeurope for rental information and pricing.
If you are dropping off at ORY, it´s very easily done as this airport is along A6 as you return to Paris. If you are dropping off at CDG, take A6 to A4/A104, the francillienne, to orbit east around the city. From the francillienne, take N2 to N104 and enter the airport from the east. Check a map or google for the details but this plan will save you time and money.