The Porsche 911 turns 50 this year. Not bad for a car with the engine in the wrong place.

What's kept it so appealing for so long? The above video is one man's explanation.

Jeff Zwart is more familiar with 911s than most. He's been in charge of Porsche's advertising campaigns for over 20 years, and has raced 911s at Pikes Peak. He learned to drive in his father's 901, and even before he was able to drive, Zwart says he was obsessed with the sound of the 911's flat-six engine.

Zwart says the key to the 911's appeal is its ability to adapt yet remain familiar.

He cites the 911's evolution from a spartan sports car to near-supercar with all of the modern conveniences, and high performance versions like the 991 Turbo S. Yet through all the changes, the car's ability to perform on road and track has remained continuous.

Zwart says Porsche's evolution-over-revolution approach to the 911 can be felt in details like the driving position and the slightly offset pedals. These touches breed a sense of endearing familiarity, he says.

Porsche's heavy involvement in motorsport has also helped build the 911 mystique, Zwart says. Having a car that's as dominant on the track as the 911 has been over the past 50 years is obviously a plus when it comes time to sell a road-going version.

Wherever you're driving, Zwart says, a 911 is the perfect sparring partner.

"It makes you a little better, it ups your game," he says.

Check out the video to hear more of Zwart's thoughts on Porsche's iconic sports car, and for some beautifully-shot 911 driving action.