And, as has been shown in this thread, this is why we have to have so many laws on the books. Too many people simply won't do obvious, easy, and in many cases free things that significantly reduce the costs to society. Hence the laws.

And, as far as entrapment goes, others are right: the OP doesn't seem to know what the word means. It would be entrapment if the police actively did something that caused, encouraged, or suggested that the OP not wear his seatbelt, and where he was not predisposed to not wearing it prior to the police action. That's obviously not the case here.