Yes, German autobahns have speed limits, though obviously not everywhere. We have them because they are absolutely necessary. Germany has more than twice the population of California on significantly less area. The traffic often is accordingly.
For the same reason, it is absolutely forbidden to overpass another car on the right except under very specific circumstances (stop and go traffic, or direction lines at a crossing). This is the other thing which this driver has done. In contrast to the costly but socially accepted offence of being 30 km/h (20 mph) too fast on a motorway, this is considered absolutely reckless behaviour by almost everybody and raises eyebrows whenever someone does it. Here is an example for what often happens when idiots do it anyway: https://www.youtube.com/watch?v=7AGwQuT0-Lk
In general, driving on German motorways, with or without a speed limit, requires significantly more concentration than driving on Austrian ones (resulting in a significant change of my stress level each time I cross the border), which in turn requires a lot more concentration than driving on a British motorway (in spite of the left-hand side traffic), which in turn is not even comparable to the child's play on American motorways. (At the other end of the spectrum you can continue this with Italy, then probably countries like India.)
The stuff installed in this car makes no sense if the driver didn't (intend to) use it while driving. Germans don't live in their cars, they use them to quickly get from A to B. That's one reason we have smaller cars. If he used this setup, then he risked lives in much the same way as "Turbo Rolf" did in 2003: http://www.telegraph.co.uk/news/worldnews/europe/germany/1454812/Turbo-Rolf-jailed-for-tailgate-deaths-of-mother-and-girl.html