Many thanks to everyone who commented and Emailed their suggestions regarding the locations used in the new Citroen DS5 commercial.
The correct locations are:
0:01 – The D3 leading up to the village of Gourdon (Gourdon can be seen in the background).
0:04 – The D2 driving east toward the village of Greolieres. This section of road is extremely popular and has been featured in numerous car commercials, movies (Ronin – beginning at 0:31 to 0:59 and Goldeneye – beginning at 2:14 (Greolieres in the background) to 3:16. to name just two), and on countless car review sites.
0:20 – On the Promenade des Anglais in Nice near the old town.
The Hotel Suisse and Hotel La Perouse can be seen in the background.
Le Stuff 
Zut! I can’t believe that I missed the last one. I spent many mornings running along the Promenade des Anglais in Nice just last summer.
It’s a quick shot and easy to miss. Thanks for your comments Brian!