(Way 2 - the shady play)
Apologize and ask,"May I pay the fine right here?"
Fish into your pocket and show him that all you have is a $20.
This is indeed unethical and perpetuates the shady mordita dynamic,
it is undeniably a quicker and often cheaper way to just be on your way.
if you go this route, do not be a sucker.
never offer more than $40 total or $10 per person in the car.
if you get a cop who's leveraging fear from you and asking for an absurd
amount over $40, call his bluff.
offer to just got to the station.

Can I get a DUI in Mexico?
yes. It's not nearly as horrific as in the U.S.
Follow the same steps as a regular traffic stop I describe above.

Is there an open container law?
just for the driver - passenger drinking seems to be OK.
Probably not a good idea to be downing a 40 while you are behnd the wheel.