Dude, California was like the microbus center of the cosmos...maybe those hip(pie) folks who used to drive air-cooled VWs are grandparents by now.
A few highlights:
1954 The 100,000th VW Transporter rolls off the assembly line in Wolfsburg. The engine size is increased, improving horsepower from 25 to 30hp. All models are made available with right-hand drive to increase sales in foreign markets and the postal service.
1963 A number of improvements are introduced, including a more powerful 42 horsepower engine, an improved lighting system including larger front turn indicators, a larger rear hatch, the option of sliding side doors, and the increase of payload to one full ton.
1965 Engine is upgraded to an output of 44 horsepower at 4000 rpm. Transporters are still passed on the highway by everything except heavily-laiden ice cream trucks, but with some persistence, they eventually catch up later that night.
1968 The first major revision of the Transporter since its inception. The new second generation Transporter features a revised body shape including a large one-piece front windshield and sliding side doors on all models. Drivetrain changes include a transmission with double-jointed driveshafts and a new 1.6 liter, 47 horsepower engine.
1975 The 2 liter engine is introduced, providing 70 horsepower at 4200 rpm. The power increase in turn allows for a new maximum payload of 2500kg. Small engine size finally pays off as owners of large V-8 powered vans are stuck in around-the-block lines at filling stations during the gas crisis while bus owners cruise on by.
1979 The third generation Transporter or 'Vanagon' is introduced. This features a complete restyling of both the exterior and interior. Gone are the round shape of the previous two generations of Transporters if favor of a more angular "wedge" shape. The interior is upgraded substantially to include the level of comfort included in modern vehicles. In addition to the body, all other systems are redesigned and improved. 1982 the Transporter now features a water-cooled 1.9 liter flat-four engine, also known as a "waterboxer".
And we're not even to the front engine, front drive Eurovan yet...