He mentions Pioneer violated the GPL by not making the source code available. Is that the case with selling embedded hardware? I thought that rule applies only if you are selling the software.
For example, many wireless access points use Linux, but you never see the source for those.
This seems to be Pioneer's GPL source code site: http://www.oss-pioneer.com/car/navi/files/ . I don't see AVIC-5000NEX there, but a variety of other AVIC devices are listed.
The GPL mandates the code be made freely available, it doesn't say how. It may require a written request sent to corporate headquarters. I don't think there is enough info in the post to say they are ignoring the license terms, but they certainly aren't living up to its spirit.
I'm pretty sure there must be an offer of source and the license needs to be somewhere. Usually for things like router manufacturers you'll see a notice in the manual somewhere and a link on the support site.
The GPL'd portions of software must be made available. They have been distributed, therefore source must be given under the terms of the license.
The GPL doesn't necessarily affect everything on the box, I'm not 100% clear on what happens if you sell a system using (for instance) GNU/Linux and put proprietary software on top of it, with regard to the source of the proprietary software. But you would have to make linux available.
The proprietary software is unaffected by the GPL so long common sense (ie in layman terms) tells you that they are a separate program with the GNU/Linux parts.
The problems comes when people want to stretch the definition of separate programs. In those cases, contacting lawyers and seeking out the authors intent seems to be the only viable option (for example, the case with Linux modules).
That was what I thought was the case, but wasn't 100%.
I worked for some folks who were making an ubuntu based network-monitoring appliance a couple of years ago, one day they freaked out about the GPL and decided (absent any legal advice) to make us port the project to NetBSD. They refused to consult a lawyer because it would be too expensive apparently, but would have been far cheaper than all the developer time... I suppose at least I got to add NetBSD porting to my cv :)
The news section mentions many embedded devices, and the court cases give you some idea about what you are allowed to do with the code for those devices.
For example, many wireless access points use Linux, but you never see the source for those.