My sister and I are taking my mother on a cruise and have stops in Marseilles and Nice. She is 83 so we don't want to wear her out, but we want to take a nice day trip (4-6 hours) to Aix en Provence (from Marseilles), and then to Monoco (from Nice). Should we rent a car and drive ourselves or is there a way to get a guide with a car for a reasonable price? Obviously we're on a budget and want to avoid those expensive shore trips from the cruise line. Thanks!