Ok you asked for it
Moving generally from the south of France to the English channel.
If you are going as far to the east as Carcassone it is well worth another 11/2 hours to see the castle of Queribus, stunning 360 views, and Carcassonne needs to be seen under floodlights, very atmospheric. Also some epic sweet shops!! Also have a wiki about the albigensian crusade before you go, and the doris can read Kate Mosse labyrinthe.
Albi is to the north and apart from being a very interesting town is the birthplace of Toulouse Lautrec with a stunning gallery.
To the west is Bergerac, picture postcard stuff, can't recommend highly enough.
Near Bergerac is the Vezere valley, very many stone age sites and one of the richest areas of early human habitation outside Africa/Asia. Troglodite village of Madeline near Tursac (even housed French people into very recent times) 1/2 hour to the NE near Montignac is the world famous caves at Lascaux, mind blowing cave art, probably 20 000 years old.
As said above Rocamadour is well worth visiting, a village and castle clinging onto a hillside.
Oradour sur Glane is a sombre memorial to a town destroyed by German troops during WW11, almost untouched since being discovered by neighbouring villagers.
Further north the town of Chinon (one of our favourites - 45 mins away) has the royal castle where Joan of Arc persuaded the Dauphin to fight against the invading (questionable) English.
There are many chateau along the Loire valley but two of the best for their differences are Chenonceau and Breze.
While in the area the tank museum at Saumur is worth a few hours, not as good as Bovington but a near 2nd.
Near the north coast is Bayeux with the tapestry, and just to the north on the coast is Arromanches les Bains site of the Normandy landings and with a superb D Day center. A fair number of the concrete cassions used to create the mullberry artificial harbour are still there in the surf.
We have visited all the above and a lot more besides. There are of course many other places to visit, things to do etc. Remember a lot of places will be shut for lunch from 12 to 2, just find an out of the way restaurant and have a "Plat du jour" for about 12 euros all in. Years ago when we travelled in our 110 we found beds in hotels near industrial estates of larger towns for around 25 euros per room for 2/3 people, most with good ensuite facilities, tv etc. If you want to keep prices down try B&B, Premier classe, Etap, Village etc, for a bit more money try Campanille (they usually have reasonable restuarants attached.
Dont be tempted to break the speed limits, there are an increasing number of cameras about. Buying fuel can be interesting, your card (if paying at an auto-pump) will be debited with something like 120 euros, you fill your tank for 95 euros (say) and your card is debited for that and then credited with the original 120. This all happens within minutes of course and somtimes a UK banks computer will flag up a possible fruaduent transaction blocking your card!!! Easier to pay with cash, but of course the kiosks will be shut from 12 to 2!!! Diesel over here is around 1.25 away from the autoroutes.
The way the exchange rate is going it would be worth changing your money now, I can only see it getting worse in the next few months, but that is your choice of course.
Anything more just ask. Enjoy your trip.