How best to get around in this itinerary in France?

A lot of folks like to stay in Paris at the beginning of the trip to get over jet lag, etc. If you did that, you'd end up in Rennes, from where you could drive/train to Nantes and fly to Munich (I think?). You can do MSM as a day trip from Rennes while you still have the car, rather than going out of your way coming from Amboise (and that's a long drive). But it seems like a car is a good choice. E.g., I didn't see a direct train from Chartres to Bourges.

This is doable and not rushed. I agree with spending time in Paris at the start of your trip. Double check the hours that your car rental office is open. In smaller cities, they often have partial hours in Saturdays and are closed Sundays. However you might be able to return a car when an office is closed by leaving the keys in a lock box.

It might be cheaper and much faster taking a plane, rather train to Munich.

Thank you for the replies so far. We very much want to spend the night on the Mont and have it be peaceful at least for a bit without the day trippers.
I already tried this itinerary in AutoEurope and it is not allowing a drop off in Rennes??

Since Rennes is on the way to MSM, depending on your timing, you could just drop the car on Friday in Rennes and jump on the bus to MSM. It runs frequently and is very comfortable (took it from St. Malo with same company).
https://keolis-armor.com/en/5ey-Going-to-Mont-Saint-Michel.html

Try adjusting your return time in Rennes
Since it’s a Saturday agencies likely close around noon

Surprised it allows pick up in Bourges on a Sunday when agencies are closed
( your pick up location might actually be the problem if that agency in Bourges doesn’t allow diff drop off location)

You can call AutoEurope toll free

Auto Europe allowed us to return our rental car at the Rennes airport (Avis), June, 2025. We took a taxi to the train station since we did not want to drive in a larger city.

If you book direct Enterprise will allow pick up at Chartres on Saturday all day with a lunch break (closed Sunday) and drop off at Rennes. Likewise from Bourges on Monday (closed Sunday) to Rennes.
Europcar are closed at Chartres on Saturday, and Sunday and at Bourges on Sunday, but will otherwise allow one way rentals to Rennes.

Hertz are closed at both Chartres and Bourges on both Saturday and Sunday.

So in general it is not that one way rentals are not possible, but that you can't pick up a car on a Saturday or Sunday, with the odd exception like Enterprise.

But then Chartres to Bourges can be done by train from Chartres via Le Mans (ie not returning to Paris) and Bourges to Amboise and Amboise to Rennes are also possible by regional trains - so you don't return to Paris until on the way to Munich. Keolis run the Rennes to MSM bus-https://keolis-armor.com/en/5ey-Going-to-Mont-Saint-Michel.html

There is also at one daily Rennes to Munich train avoiding a Paris change- at 0622- change Brussels and Frankfurt, so you could front end Paris then just go straight from Rennes to Munich. Yes it is a 13 hour journey, but an option.

If a 13 hour 3 train journey is too long then at least in theory Air France fly from Rennes to Munich with a connection at CDG. Not checked timings so it may not work in practice.

If you front ended Paris, you could take a direct Paris to Bourges train, then work west by train- Amboise, Chartres and Rennes in that order to avoid backtracking

Tammy, I'd start in Rennes where there are a lot of car rentals at the train station and map out your itinerary from there. If you end in Chartres, you just take the TER (local train) to Montparansse station in Paris. Or, drive the car as far as Orly airport to drop off and take a taxi to your Paris destination.

I'm not sure how important Chartres and Bourges are to you. I would take the train to Tours and rent a car there. It is really nice to have a car to tour the Loire chataux. You can drive to MSM - I highly recommend spending the night - and drop the car at Rennes to take the train back to paris (or Munich). The area around MSM is lovely to drive around if you have time. I think I dropped my care there on a sunday, but if you need to change the drop off day, you can probably do that. Enjoy - it's a lovely part of france. sue

As mentioned, the rental car offices hours are limited on weekends. There are rental places at Saint-Malo, but they are probably worse. Keep in mind that even is a rental office is closed, you can often drop your car off. I have dropped off in Caen during times the office was closed. Just make sure to take copious pictures of the car after you park it so you can verify it was left with no damage.

I would check that the car rental office is open on Sunday.

My recent experience with renting a car/driving in France.

Our rental was picked up in Caen and the only two options allowed by Enterprise at this location were return to Caen or return to CDG. We opted for return at CDG which was a nightmare. I would never do that return through Paris traffic again. I found driving in Normandy and Brittany pretty straight forward as long as there was someone “navigating” besides me so I just focused on driving. I had watched a few you tube videos about driving in France before the trip and the tips from those were quite useful. We opted to pay a bit more for an automatic and I was glad I did. I can drive a manual, but the automatic made it one less thing to deal with while driving.

I like your idea of spending the night on MSM.

I am going to suggest a great flat in Amboise. La Leonardine a duex pas du Chateau Royal. We booked through Booking.com. Bright, spacious, well located and with free dedicated parking spot off street. It ran €110/night in Sept ‘25

I’ve noticed that AutoEurope doesn’t add EuropeCar rentals until 6 months out*. If I were you I would plan as if I can drop off in Rennes.

*maybe I’m wrong but in my last two trips this was the case and led to a significant drop in the rental car cost because EurooeCar was the cheapest.

As for where you start, I’ve done 2 trips where I train directly to Amboise from cdg and one where I landed at orly and drove directly to Chartres. I prefer this approach to one where I’m sleeping in Paris at both the start and end of the trip.

I'd start with Paris as others have mentioned, and perhaps pick up the car in Paris Orly to have more options than in Chartres. Then drive to Chartres, Bourges if you must (but I suggest Le Mans instead, shorter drive and lots of late medieval architecture too!), Amboise, Le Mans if you follow my suggestion, Mont St Michel, and return the car in Nantes for the flight to Munich.