Last year the BMW X5 received some modest updates that included up to 4,000 new parts, BMW says. Since the exterior and interior look pretty much unchanged since the SUV debuted in late 2006, most of those changes are underneath the hood. The new turbocharged six-cylinder feels punchy, but the eight-speed automatic transmission bungles acceleration, Cars.com editor Kelsey Mays says. Overall the luxury SUV is aging gracefully despite some design quirks.