Like violins, cars announce their need for a tune-up by squeaking shrilly and leaking oil every time you play Mahler. Keep your ride purring pleasantly with today's Groupon: for $18, you get a full-service oil change, which includes a 21-point inspection, at Pro Oil Change (a $49.70 value). An additional $3 supply fee may be required.

Pro Oil Change's trained mechanics drain sludgy car fluids seven days a week and replace them with up to 5 litres of standard Valvoline oil. During the 15- to 20-minute warranty-approved service, which does not require an appointment, technicians send clean lubricants into the engine and cap them off with a clean, standard oil filter, which protects the engine from dirt and rumours spread by gossiping tires. Technicians then refill dwindled fluids and take a 21-point safety tour of the vehicle. During the inspection, mechanics glance at tire pressures, inspect the exhaust system, fiddle with the lights, and check the battery to make sure it's charge isn't being pirated by wind-up music boxes. While cars guzzle new fluids, drivers can relax in a comfortable waiting room, watch TV, and sip complimentary coffee, tea, or hot chocolate.