BMW makes over the 3 Series sedan, wagon

BMW has made some big enhancements to its best-selling car line, the 3 Series.

For 2016, the 3 Series sedan and wagon have a redesigned front end, including new LED headlights. There's a new inline six-cylinder engine that develops 320 horsepower. There's also redesigned electric power steering to make the car handle better.

There's a lot at stake for the BMW. It says the 3 Series is its most successful line, making up about 25% of its sales worldwide and pulling annual sales of 14 million. It's been around since 1975. BMW knows that it makes changes in it at its own risk.

In the end, it's largely about the looks. The 3 Series front end gets a sharper, sportier design, partly due to the new headlights and optional LED taillights.