Let's see what the statute says... oh! There is this - from MCL 257.710e:

(6) If after December 31, 2005 the office of highway safety planning certifies that there has been less than 80% compliance with the safety belt requirements of this section during the preceding year, enforcement of this section by state or local law enforcement agencies shall be accomplished only as a secondary action when an operator of a motor vehicle has been detained for a suspected violation of another section of this act.

So wait a minute, this law could be kicked by non-compliance eh?

But here's the question: How do you determine compliance rate? Clearly there are people that say "piss off" to this law, yet don't get caught. For those who do get caught, what are those numbers compared to to get a percentage of non-compliance?