After completing the game, use the "Select Mission" button to start any mission. Before game play begins, a menu will appear with all available cars and upgrades. You will have all money accumulated during the storyline and should earn "Financial crysis? NOT!!!".
Easy "Kill and destroy" Achievement
This requires a lot of zombie kills and object destruction. Have a machine gun that is upgraded fully, and a flamethrower for use in narrow spaces that contain boxes and other objects. Keep riding and shooting to get a +30 seconds bonus. Killing zombies will result in more time, but there are many more objects to destroy. The most efficient way to maintain a running combo is to keep driving while shooting the machine gun. "Kill and destroy" will be earned when the combo is converted into extra time, which happens when you stop destroying and killing, or when you run out of time.
Easy "Stand out from the crowd" Achievement
Win all tournaments, including the tropic tournament from the Tropical Race Rage DLC. Note: Tropical races are open and are best won using faster cars instead of heavy ones.
Easy "They didn't see anything but my rear" Achievement
Win every tournament with at least a bronze medal, then start "Single Event". Choose the ones where you did not earn a gold medal.