I finally went and did it. I got a new car. The 2002 Buick LeSabre just had too many problems, and the next big repair was going to cost more than the car's worth. So I bit the bullet (a week after talking myself out of it) and got this 2012 Ford Fusion.
It's got much better mileage than the Buick (37 mpg versus 28 highway). I can't wait to take it on road trips. I want to explore this great state.