Area: Hoover Dam
Category: Break specific stuff
Vehicle type: Either
Goal: Destroy poles, then all vehicles, then cars
Score for Gold: 2:14.56

Strategy #1:

Very straightforward. Follow the on screen instructions. When destroying light and utility poles, you can shoot them out or run into them, both methods are prone to missing a direct hit. The roadway across the dam is a good source of light poles. On the other side of the dam from the starting point, as you travel a guard rail begins on the right, then another on the left. Position yourself about halfway between where the guard rail on the left begins and the utility pole that appears on the right a short distance further down the road. If you are in the right place you are right between two vehicle spawn points. Destroy a vehicle, turn 180 degrees (it's easier if you turn clockwise), and repeat, and you will get an endless fast supply of vehicles. When it says to destroy just cars, continue to destroy all vehicles anyway.

Strategy #2:

Transform into jet then boost down all the poles on the right, until you have 8, tranform back, turn around and tranform back into jet and get two more poles. The keep shooting at the ground and boost at the cars which destorys them, do the same, to the cars as well.