Bonjour. Try this website for some help: wikitravel.org/en/Aix-en-Provence.

Rick Steves in his Provence Guide says: " Day-trippers should look for the Rotonde parking area , near the T1. If you miss it, follow signs for "gare routiere" (bus station), and park there. Allow 13 Euro for 24 hours"

We found that it is always smart to park outside the lovely villages and cities in Provence --- the walk into the village is so much easier than the hassle filled traumas of trying to maneuver through trafficked streets with little available parking and lots of tourists. You will have a wonderful time in this fine city.

Also check out: www.aixenprovencetourism.com