The 2010 Ford Fusion is a car that blurs the boundaries between a midcycle refresh and a ground-up redesign. Its platform is shared with last year's Fusion, which means it's still fundamentally a stretched version of the first-generation Mazda 6. Yet practically everything else is new -- exterior design, interior design, powertrains, you name it. Before you write off the 2010 Fusion as a warmed-over version of the previous model, we suggest you take one for a test-drive. The old Fusion was already a pretty good midsize sedan, and thanks to Ford's determination to rectify its flaws, the new one's even better.