Cars 2: The Video Game

I found the easiest way too do this was on the 3rd training part called C.H.R.O.M.E. Advanced Maneuvers. I believe its on the 2nd part of this where you have too side bash cars. Just don't exit when you pass. Keep driving around, you can speed up around the bends but when it comes too the straight aways with 5 cars lined up in the middle be sure too take it slow and side bash each as you pass. After about 10 laps achievement will pop.

Set up for two players to play, then enter the C.H.R.O.M.E. training missions. I did this on the Advanced Manoeuvres level. Wait until you take control of your vehicle, reverse so you are beside the inactive player, then just keep slamming them. They will not die, so there is no waiting to respawn and you'll have it in about a minute using this method.

Here is an easy way to quickly get this achievement taking advantage of a poor respawn implementation and two controllers.

Start up two controllers and go into arena mode. Set the number of kills to 20 and start the match.

When the match starts, drive over to where your opponent spawns and kill him. When he respawns this will be the location he will respawn after each death (it was on the London Arena), so drive up and park right beside him. Now, hit the RS to either the left or right twice (depending on which side of your opponent you are on) to side bash him and he will explode. Quickly hit the RS the opposite way you went to kill your opponent to get back into position for his respawn. He will respawn exactly where he did last time, bash him again. Rinse and repeat until you hit 20 kills.

When the match ends, select restart to get another 20, rinse and repeat until you get 100. Took me less than 10 minutes.

One side note, if you have any forward or backward movement when hitting your opponent it will cause them to move forward for back, so make sure you are completely stopped when you hit him.

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