The video shows Volkswagen's testing team taking various models out into a proving ground of some sort (if you can call it that, it's more of a crash derby/motorcross pit), and punishing them to the point that the tyres burst or at least something is broken.
For example, the team of testers take a New Beetle onto a severly corrugated piece of road, at speed, and then slams the brakes just to see how the ABS and suspension copes with it. The video also showcases some pothole testing, while turning a corner and slamming the brakes. The team even puts a Transporter van through its paces by taking it up to high speed and then launching it over a large BMX-style jump.
If you think cars aren't made as tough as they were in the Sixties and Seventies, how does ramming a set of four wheels at speed sound? Or, smashing the undercarriage of a car with large blue metal rocks and then ploughing into a big pile of them shape up? Take a look at the Volkswagen video below for all the tests.
It's actually quite funny seeing what torture Volkswagen were prepared to put its cars through just to ensure durability. Of course, testing these days is a bit less crude and is done using state of the art technology. But some strange testing procedures are still in practice. Take a look at this recent Audi durability testing video below for comparison.