The time you lose is far outweighed by the extra multiplier you will gain. You're almost better running (or stealing a car) and driving to a better part of town than staying where there's not much to shoot at. It helps to move into a target-rich area, like a suburban street where fences and small items litter the scenery. You should be firing off rounds as fast as you possibly can, and blowing absolutely everything in sight to kingdom come. The most important thing though, is just keep shooting. If your multiplier is super high, target expensive cars to get a huge points bonus. It's relatively easy to hit 30-50+ multiplier in non-Tank Mayhem, which means you'll be racking up the score in no time. Alleyways are positively littered with things that explode for cash. If you can find a roadside cafe, a street market, or a line of fences, you're golden. You get credit for destroying almost EVERYTHING, so driving/running down the street and firing a RPG or the tank cannon repeatedly into the sidewalk is a good way to go. In the Mayhem levels, the trick is to get a high multiplier and keep it there.
