To tell you the truth...
Unfortunately, I muts say that I see no reason why TomFulp found this game so interesting that he put it on the front page. Here are a few reasons:
1. The first level was even hard. Seriously.
2. It was hard to reach the vehicles when useless brown boulders were in the way. Accidentally grabbing the stupid oversized rock depletes time, which you barely even have on the first level.
3. Stacking the vehicles required perfect vehicle placement. I can't count how many times I failed at making a full pile of cars because of the pile toppling over before I completed it.
4. It was too repetitive after the first few levels, and eventually got boring.
So overall, this game isn't very good. But I can see by your Flash skills that you can make something better than this. Just please, have different objectives, rather than just collect cars and then piling thenn and compacting them.