Car Demolition Clicker

This will probably be the final achievement you will go for. I used "Proving Grounds" (The one between Alley Night and Gas Station) to farm the remaining diamonds I need. Soft reseting wasn't faster than this approach for me. This level has the least available cars to finish, and higher chance compared to other smilar ones. It is the optimum one (time wise) to use for the grind.

In addition, once the level finishes, if you successfuly defeat the boss, you will have to restart the level yourself. Therefore, put your mouse cursor on the point where you click to start the level, then run your auto-clicker. This way once the level finishes, it will restart automatically.

You have to collect 50 "The Mob" and "Lab Rats" faction points to unlock the Observers faction. Each car destroyed grants you one faction point after choosing your faction.

After each soft reset, you will be able to pick a new faction therefore you need at least one soft reset to achieve this one.