I have 30+ years in the software industry. I've worked on/in/around everything from 8 bit microcontrollers to IBM big iron. Given a system as complex as cars have become ... yeah, it would be all too easy to hide significant chunks of code in there. I have zero confidence some fed flunky or lowest bidder contractor could effectively ensure anything about them.
The 0bamacare websites and the underlying software, show just how good a government agency can oversee a project.
Not low bidders,first year costs exceeded total costs for the top 10 US sites!