You've got to know where to go and how to travel. Don't show your wealth. Keep to well policed areas unless you are accompanied by trusted, well-connected locals, but don't give police any reason to interact with you. Dress down.

Keep to tourist areas whenever possible and project an image of being a typical tourist... i.e. a job slave who is running up debt on a credit card to seek a short-lived break from wage slavery. I use only cash in Canada but I use a credit card when traveling. It makes me look more like a tourist.

Of course away from tourist areas I use only cash. Everybody does. Nobody in my area has a bank account or credit card. There aren't even any banks in the area. That's one reason I love it there... no banks, no phones, no criminals, very few cops. Just sunshine, fresh air, good food, cheap booze and a certain little hot-blooded chilanga.

The reason I'm taking $30kUSD down is to finish paying for my zirconia teeth, pay off a personal loan, and make improvements to my house down there. I'm in the midst of major infrastructure upgrades... new 220v/120a wiring, water heater, upgraded security, etc.

I can only take $10kUSD down on the plane with me but I'll have a traveling companion to carry another $10k. The rest I'll put on my credit card and begrudgingly pay the cash advance and exchange fees. I don't have a bank account in either country. I'll spend the $20k cash almost immediately on the dentist and debt repayment and then live off my card.

I hate banks.