Well I don't think I'm getting the $100K action. But, because I'm a complete sucker, and can't wait for people to tell me I'm an idiot and breaking every law of physics, I suppose I'll post a few of the ways to do this.
First way: already posted. Put sails on the spokes of the wagon wheels and articulate them so they deploy only when beneath the axle. Not terribly practical, but works in theory.
2nd way: Imagine a big yo-yo. Wrap the string around the axle until it reaches half the radius of the yo-yo. Set it on edge so it can roll - with the string exiting beneath the axle and parallel to the ground. Put a parachute on the string. Wind pulls the parachute at near wind speed. Yo-yo rolls up the string as it's being pulled. Yo-yo approaches 2X wind speed. This one is more "illustrative" as it comes to an end when the yo-yo has rolled up all the string and reached the parachute. It also has the downside that the parachute can be considered part of the vehicle, and it never exceeds the wind speed. But it helps some people see the idea.
3rd way: tack downwind with an ice-boat. Yes - tacking downwind can yield a downwind component faster than true wind speed. It's easy enough to post the vector analysis if need be. Well that's not "directly" downwind you say. True - so build a big light frame around your ice-boat so the frame goes straight downwind while the boat tacks inside of it. Still no good you say because the C.G. isn't going directly downwind. Fine - put two ice-boats in the frame and keep them on opposite tacks.
4th way: build a land vehicle with a propellor on back that is geared to the wheels such that the tangential speed of the blade tips is equal to the speed the vehicle goes downwind. This will yield wings that are in a continuous spiraling "tack" 45 degrees downwind. This one is really peculiar. The prop doesn't cause the wheels to turn. The prop pushes the vehicle, which causes the wheels to turn, which turns the prop, thereby constraining the tips to thier 45 degree downwind tack. And NO, this is not a perpetual motion machine. It will only work so long as the wind blows. And NO, the vehicle will not just keep going faster and faster.
5th way: You kind of have to look at this one upside down and backwards, but this one happens everyday. Imagine you're in a sailboat drifting with the current on a day with 0.0 mph wind. But the current is 10 knots. Well that gives you an apparent wind of 10 knots over your bow (current pushing you through still air). If you want to go where the current is already taking you, but you want to get there more quickly, you can raise your sails, and tack into the apparent wind. The current is "pushing" you - but you're beating it to it's destination. Since the sail and the keel are both just wings in a fluid it works the same right-side-up or upside-down. Given that the constant 10 knot current is a valid inertial frame like any other, we know this is no different than tacking upwind in 0-current and a 10-knot wind. So anytime we tack upwind it's equally valid to see the water as a constraint while we tack into the wind, or the air as a constraint as we tack downstream faster than the stream.
People frequently think it's impossible to "outrun" the motive force of the wind, but we have to keep in mind the energy we are extracting is that of the relative velocity of the air over the ground or water - not over our vessel. We do have to get creative to come up with ways to do it however.
Head down - flamesuit on. I know the drill.