I highly recommend a car. We took the train from Paris to Avignon, then rented a car, visiting Avignon and Chateauneuf-de-Pape. Then we drove to the Luberon area, spending 4 nights at Le Mas Jorel in Gargas. While there, we took day trips to Isle La Sorgue (wonderful market), Roussillon, Gordes, Goult, Lacoste, Bonnieux, Loumarin. and Saignon. The Abbey of Semanque with lavender fields blooming was fantastic. Then we drove to St Remy and stayed for 3 nights at Mas des Tourterelles. We enjoyed wandering around St Remy on market day. The ancient ruins were very interesting, as was the Van Gogh drive and asylum. Our day trips there included Arles, Les Baux (light show touristy but really interesting) and Pont du Gard. Along the way we had picnics and wonderful meals while exploring. We could never have done all this without renting a car.