This isn't something that is easy to do. You need to interact with probably 12 people any of whom could trivially copy the data off the machine and whistleblow you.
Criminal behavior implies something minor. Murdering a dissident isn't minor.
Of course, those 12 people could also expect to receive the same kind of 'sanction' that they just witnessed. And since their employer has access to all their personal communications while in the car, the company has access to a wealth of the most sensitive personal info that's almost trivial to abuse, if in fact retaliatory murder WAS considered to be overkill.
That might be enough to dissuade them from whistleblowing. (That and the fact that whistleblowing is nearly always a great way to commit professional suicide in this country.)
Criminal behavior implies something minor. Murdering a dissident isn't minor.