Lvl.6: Three S.W.A.T. cars and four larger cop cars. S.W.A.T. cars have assault rifles, and you can't get in them. Assault rifles are less accurate then the pistols the cops have, but are automatic. Still two hit kill. Lvl. 8: Ten S.W.A.T. cars, two of which armed with machine guns. Less accurate than assault rifles, one hit kill, lower rate of fire than assault rifles. Lvl.9: Seven military jeeps with mounted Machine guns on back, and an assault rifle in front. You can kick them out of those. Two S.W.A.T. cars. Lvl. 10: Five of everything mentioned earlier, double the roadblocks, and truck driver roadblocks. Basically a truck with the back opened. Make them rare, but if you get caught in one, you lose all your "continues." Also, if you slow down for any reason for five seconds straight, a tank comes in.
Every 10 thousand points, add a wanted level which brings cops. Make 10 levels of wanted- Lvl.1: A cop car. At this level, you can kick him out, but he tries to crash you. Lvl.2: Two cop cars. You can still kick them out of the car, but he is as fast as you and is better at crashing you. Lvl.3: Two cop cars, one of which has an armed officer. If two bullets hit you while you are on top of a car, you die. You can't kick the armed officer out of the car. If you try you die. Lvl.4: Four cop cars, three of which have armed officers. The cars are bigger and harder to crash. You can't get in any of these.