We like our favorite
creperie in the 14th arrondissement ("Creperie O Bea Ba" on Avenue Rene Coty). It's a locals' place, no tourists. Also a couple of nice cafes around Chatelet (i.e. Sarah Bernhardt Cafe). Paris has very good public transport (RER to the airport, and the Metro). If you go outside Paris and need to rent a car, I recommend SIXT (a German company from Munich, good car selection...