- Rollin', Rollin', Rollin'
This is one of the more agitating achievements in the game. It doesn't seem like you can run over any vehicle that's bigger than a normal police car. It is also very easy to get stuck on top of a car. I found the best farm for this was roll around in a tank and watch for police cars. Once there were too many destroyed vehicles in the way, i'd either save and quit to despawn the debris, or let myself get arrested to clear the debris.
- One Track Mind
Once you have access to buying a tank, roll around in it. As your wanted level increases, tanks will begin to slowly spawn. You can find them after hearing a notification on the radio saying a tank is on the way.
You can keep track of how many tanks you have killed on your statistics page in game.