I lived in PV more than six years. A 200 peso roadside "tip" would have settled this. When I still had US plates, I was stopped seven times in PV. (I drive like a Mexican, and was doing something illegal each time.) The police were always courteous, and non threatening. In my opinion it's foolish to waste your time taking the ticket. For me, a stop is a twenty minute distraction, and a cost of 200 pesos. They always want more, but I speak Spanish, and the police know that I know the going rate. Comparing this to the time and money that I would waste in the US or Canada (not to mention the fact that it would go on my record), a police stop always reminds me of how free I am here.
I also have heard that they can't take your license, but who knows. The system is what it is.
I should say, that my Mexican friends hate that I pay, but I choose expediency over principal.