Easy Bolts:
Use the following trick to get 150,000 Bolts in 45 minutes. Get your helipack on Metropolis, then go to the Gagetron all the way in the beginning. In front of the Gagetron, (aiming towards the big person with the wrench who spins around) jump down and turn around. You should see a tunnel. Go into it for a gold Bolt, and break all of the boxes. In 15 seconds you should have 2,073 bolts. Then, fall down and repeat the steps all over again, except for the helipack