I was thinking of voting machines as well and think publicly verifiable code and hardware would be a good thing for cars (I don't think it's good enough for large scale elections, but that's another topic).
ps. just reading this in a post from Bruce Schneier[1] that is currently on the frontpage as well[2] which is about cheating software as used by car manufacturers and the IoT that is coming up:
Voting machines could appear to work perfectly --
except during the first Tuesday of November, when it
undetectably switches a few percent of votes from one
party's candidates to another's.
See this story about the need for open source for large publicly used systems: http://www.nytimes.com/2015/09/23/nyregion/volkswagens-diese...