The Fusion (the older one) is actually based on the Mazda6. Ford stretched the wheelbase slightly and put a boxy body on it, and voila, a Fusion. It is a super reliable car with the four cylinder engine. The six in both the Fusion and older Mazda6 models was a Ford engine that had a lesser reputation. For that car the four was quite adequate. I prefer the styling of the Mazda, the Fusion’s chrome barred grille being a bit much. It also came as a Mercury Milan with a more understated grille. The Fusion outsold the Mazda6 by a bunch in those years so you’re more likely to find a good deal on the Ford, but as you’re in a larger market the Mazda won’t be too hard to find.
Former rentals can be a good deal if you can find someone selling the model you want. Fusions were very common in rental fleets and I did have a Mazda6 once, so there might be some around. Rentals tend to be two-to-four years old and have fairly high mileage for their ages. The big rental firms have their sales inventory online so it’s easy to see what they have. It’s also nice that most sell at fixed prices. They also typically keep good maintenance records.
I wouldn’t worry about reliability if a Mazda6 has been decently maintained. Both the Mazda and the 1st generation Fusion have excellent reputations, quite comparable to other mid-sized Japanese models (even if not made in Japan). If I were in the market for something of that Ilk they’d be way up on my shopping list, though I’d probably buy a Mazda3 hatchback as I’m quite partial to hatches and there hasn’t been a Mazda6 hatch or wagon for quite a few years. Back when (2005-2008, approximately) I coveted the Mazda6 wagon seriously. If you see a pearlescent off white one, my heart was lost to it many years ago. Alas, it only came with the six, but I don’t demand perfection in a lover. As you might have guessed that’s one of my all-time favorites. Such a pretty car. The hatchback was sweet, too, if not as captivating as the wagon. The 2009-2012 generation is what you’re likely to see. It only came as a sedan and the styling was not quite as pretty. It was quite a bit roomier and is a very fine car, just not my great love.
Mazda is one of my favorite automakers. For a smaller company they make wonderfully engineered cars with a lot of style that also drive very well. Unfortunately, they are having a tougher time now than when Ford owned a big chunk of the company and was paying Mazda quite a lot to develop small cars for the US market. Now Ford is having Ford of Europe develop all their small cars. So Mazda has to pay all their development costs themselves or find other partners. They did that with the new Miata, which is also providing the underpinnings for an upcoming Alfa Romeo roadster. Fiat didn’t have a suitable rear-drive small platform so paid Mazda for theirs. The engines will be Italian.
Eventually Mazda will likely be bought by some much bigger automaker as they have very attractive engine technology that gives excellent fuel economy and make mainly smaller carss. As corporate fuel economy standards get harder to achieve, buying Mazda could give another maker a way of getting their CAFE down by bringing all those little Mazdas into their stable, in addition to giving them especially efficient engines. Mercedes would be a reasonable candidate, if they could overcome their excessive pride (as they didn’t in taking over Chrysler).
Other interesting cars are the Hyundai Sonata and its close relative, the Kia Optima. The older Optimas, before 2011, are good cars, but utterly anonymous. They look like they were designed to be forgotten immediately. Sonatas of that era are pleasant enough, with styling much like an older Audi. However, the more recent Optima is possibly the most German looking Asian car ever made (their lead designer came from Audi). It’s a very sleek car and reasonably reliable, too, but prices should be quite decent. The Sonata of that same generation is also a very nice car, if not quite as classy as the Optima. Neither will have quite the fuel economy of the Mazda, but they are OK, and very nicely equipped for their price. The Nissan Altman is another reasonably nice option, with some years better than others, but most OK. These would be better choices with a manual transmission as Nissan was an early CVT adopter and they have sometimes proven troublesome.