They could be providing lots of extra unrelated source code packages to the guy, perhaps just to be thorough and to avoid missing anything, perhaps to just fill the DVD (don't let those ones and zeroes go to waste!), or perhaps to mess with people :) (e.g. throw in a SNES emulator source code to make hackers spend days searching fruitlessly trying to figure out how to make the BMW interface start playing Mario)

Hypothetically, the car might be able to print its own systems report during manufacture. This might not be an entirely far-fetched theory given that a car contains numerous independent computers networked together and not all of them have direct access to a display.

Another possibility is that a "printing" metaphor is being used to communicate certain things between the various car computers. For example, if there's an engine fault, the engine's computer might "print" the fault report to the center console computer. On a modern BMW, the centre console computer shows a log of faults as well as a full service history and upcoming servicing requirements.

You can use LPR to spool audio files to a "printer" that queues those files to be played over speakers. There was a project called gutenbach to do this with CUPS, but last I heard the maintainer went off to grad school. Maybe they are doing something similar?

From what I can see and guess, they seem to be using one of Freescale's reference implementations...probably for the i.mx6, but don't hold me to it. It's got a lot of packages in there that aren't relevant. It's also interesting that they've also included all the source for an sh4-based microcontroller that's somewhere in the chain. Car systems are complicated these days.