times I refused to pay the bribe that they clearly wanted and asked for (“para un cafecito” — money for a cup of coffee), and insisted that they write up a formal ticket, or go down to the police station. Both times the cops just went back to their cars and drove away. It evidently wasn’t worth their time and the hassle to issue a real traffic ticket (and have to explain/defend it in court), or argue further with the foreigner to pay a bribe.

I always carry an International Drivers Permit when I drive there, and many other countries, in case the cops insist on holding onto it if I don’t pay a bribe. These permits are cheap and easy to obtain in the US (I always get them at AAA), so it’s easy to replace one if a cop keeps it. And they allow you to drive legally in Mexico and many other countries.