My wife and I just got our primary car back from its 75,000-mile tune up. It’s a 2002 Mazda Protégé, a great car that’s given us no trouble, gets around 30 miles a gallon on the highway and accelerates with real zing from a stop or when merging onto a highway. We did need to get a gasket replaced this time, which, along with the service, ran us over $400. We bought the Protégé when we lived in Hoboken, New Jersey, and if you have ever tried to find parking there you know the distinct advantage owning a small...