http://ingenuitywelcome.com/game/
Get the coconuts to the shredder! I've only managed 80% efficiency so far, but I like the look of my design.
EDIT: 81%
That game's a lot of fun.
And easy to break once you figure out that you can
build a bucket in the coconut thing to pull the coconuts out without starting the timer, drive all the way to the end, and then hit start to win in 0:00 at 100% efficiency.(Highlight for spoiler)
Also, you can build "behind" the green toolbox, as long as you don't click on any of the buttons. (Passing through them works, though.) And dragging parts outside the Flash object works, too. (Great for building a long ramp out of a rectangle to bypass some of the bumps in the road. Scaling the whole page 50% in Opera + long beam to drive over = 20 seconds saved and about a 40% increase in efficiency without changing the vehicle or driving strategy. Gotta love it.)
Another fun tidbit: faster computers give you better times, because the timer goes the same speed regardless of how fast your computer is running the car. Scaling down the window helps a lot.