I found out that you can actually start up solo lobbies and do acheivements that do not require kills due to you being completely alone.
At main menu click "Create a Game" then choose the map you desire, so for this achievement it is "Toybox Assault".
Then down the bottom of your screen, Tick the "invite Only" button and press "P2P" this will take you to a lobby and you can just press "Force Start Timer" and away you go :)
For this achievement just go onto the RC track and jump over the cars as they come around, extremely easy and just down to timing your jump right, after 5 times it will unlock!