I'd check the tint laws for your state; if there's a clause allowing for much darker tint provided you have two side mirrors and the front side windows (those that you view the side mirrors through) meet legal opacity requirements, you should be good. And it never hurts to have a copy of the statute handy, if you present it to the cop right ("I wanted to make sure I complied legally with all requirements before performing the modification so I looked it up, here's a copy Officer").
I'm basing all this off my experience in Texas 20 years ago. All of the common-sense answers on here (tint & trailer arguments) should be enough to get you out of a ticket, but we all know cops over-stepping their bounds happens...