Tomorrow I will give up my car. First alternative will be to walk, to take the métro or the bus, sometimes a taxi... the train and exceptionally rent a car. I still have some thoughts to buy a scooter, but I will "wait and see". My children and some others say that driving a scooter in Paris is dangerous.
Have you thought about how nicelooking some of the Paris métro stations are? They are the original ones, created by Hector Guimard between 1900 and 1913 in the "art nouveau" style. http://lartnouveau.com/artistes/guimard.htm