My best advice to you is don't screw with the IRS. They have more powers than any other legal creditor that I know. Just take your medicine and move on because you always be wondering if they'll come after you in the future. A guy with whom I work neglected to pay the "correct" amount and the IRS was all over him like a pet 'coon. He had to declare bankruptcy because he couldn't pay his credit card bills, his boat and back taxes. It may look easy and you may evade detection but if you're caught you're toast.
I'm assuming that the amount in question is considerable so you have to crunch the #'s to see if you're comfortable taking the risk. For example, $50,000 might not seem like a great deal of money, but I bet you would owe a minimum of $9,000 in penalties and interest after just 3 years.
Good Luck