This was another model of the winner entry for the TRIPLE contest, hosted by www.eurobricks.com.
More about the contest here:
-wind-up propulsion, or towing
-part count: 499
-size: 18 x 31 x 15,5 cm
The winding-up works by pulling an axle which makes the wind-up gear mash with the gear of the main drive shaft. Rotating the axle adds energy to the pullback motor. By pushing the axle back, the wind-up gear releases the main drive shaft and the model starts moving.
More pictures can be found here.