Tangentially, I put “open source” in scare quotes because the car scenario highlights a new but important split in the open source and free software communities. The Open Source Initiative’s open source definition allows use of the term ‘open source’ to describe code which is available and modifiable but not installable on the intended device. Traditionally, the open source community assumed that if source was available, you could make modifications and install those modifications on the targeted hardware. This was a safe assumption, since the hardware in question was almost always a generative, open PC or OS. That is no longer the case- as I mentioned in my original car article, one might want to sign binaries so that not just anyone could hack on their cars, for example. Presumably even open source voting machines would have a similar restriction.
Another example appears to be the new ‘google phone’ (G1 or Android). You can download several gigs of source code now, appropriately licensed, so that the code can be called ‘open source’ under the OSI’s definition. But apparently you can’t yet modify that code and install the modified binaries to your own phone.
The new GPL v3 tries to address this issue by requiring (under certain circumstances) that GPL v3’d code be installable on devices with which it is shipped. But to the best of my knowledge no other license is yet requiring this, and the v3 is not yet widespread enough to put a serious dent in this trend.
Exactly how ‘open’ code like this is is up for discussion. It meets the official definition, but the inability to actually do much with the code seems like it will limit the growth of constructive community around the software for these types of devices- phones, cars, or otherwise. This issue bears keeping in mind when thinking about openness for source code of closed hardware- you will certainly see ‘open source’ tossed around a lot, but in this context, it may not always mean what you think it does.