Once you stalk the Mickey D's and find that all of those are in place and it is semi-busy pull into the drive through and order something completely random.( I say Number 1 with a coke because it is so basic.
Wait your turn in line until you get to the first window where you pay. When the cashier tells you the total, act like you're going through your wallet the with a sad expression and a few swears simply say after holding up your empty wallet, "I'm all out of cash, I'm really sorry. Can you please cancel my order for me?" They will.
After that, DO NOT exit the drive through lane, simply stay in it as though you are getting a meal. When you finally make your way to the next window, act as though you are getting a meal, not the meal you ordered though. They will hand you the meal of the person to the rear of you, which is why it's crucial that they are busy and there is someone behind you.
Take the random meal and go on your way with whatever they ordered behind you. Enjoy my friends, you have just scored a free meal. I try to cut off minivans because they usually have a lot of food. I've done this many times and I wish you luck.
OR better yet go when it's busy or a bus pulls in and they just yell out orders and wait for the person who has already paid to take it...simply take other peoples food and say it's yours =D