Seven generations of Passat have graced streets around the world, and today is the long-running Volkswagen's 40th birthday. Looking at the car today, it's hard to imagine that it was offered as a hatchback in its first and second generations, in addition to the sedan and wagon body styles. But there's no question Volkswagen has sold a lot of Passats over the years, with over 20 million produced.

VW started delivering the B1-generation Passat on July 25, 1973, and sold it until 1980, when the second generation came out. The B2, which went by many names in different markets, was produced from 1980-87 (longer in some markets, such as China, where it was produced until 2012) and featured technology you might recognize in many of today's VWs, such as a turbo-diesel engine option. The B3 generation was produced from 1987-93 and, styled with aerodynamics in mind, starts looking more like a Passat in this writers opinion. The B4, produced from 1993-97, was safer and had a stiffer body but followed the same formula as the previous generation.

The B5 Passat stepped up the quality quite a bit from the previous model, and it came with a wide range of four-, five-, six- and eight-cylinder engines. It was produced from 1996-2005. The sixth-gen Passat was produced from 2006-09 and could be had with a double-clutch transmission for the first time. It even spawned the good-looking Passat CC, which became its own model in 2010, when the current B7 Passat was released.

The B7 is a curious model. While Rest of World markets all get the same car, the US produces a unique Passat for its own market, and China makes a derivative that VW sells there called the New Midsize Sedan.

Give in to nostalgia and check out the gallery we've included to see how the Passat has evolved over the years.