BMW M5 birthday celebration

BMW has a secret, and it's not telling. The brand's M Power blog is celebrating the 30th anniversary of the M5 and is taking a look back at previous models of its Autobahn-storming sedan, but it says that it will end "with a surprise." The celebration kicks off with a short video showing the latest M5 making some smoky donuts.

The original M5 debuted in 1985 and was the company's most expensive model at the time. Still, it packed a 3.5-liter six-cylinder generating a claimed 282 horsepower (286 PS), which was rather potent in its day. The company touted it as the world's fastest production four-door sports sedan at the time.

BMW won't reveal the surprise until it has chronicled all five generations of the M5, but it wouldn't be shocking to see an anniversary edition model appear sometime later this year. Scroll down to check out the video of the muscle sedan celebrating its birthday the only way it knows how.