Complete all 168 Championships.-50G

This will take a long time but is not difficult provided you use the assists/difficulty settings that suit you. As you progress further into the game you will have the option of selecting what event you wish to race and each time you complete an event it will be marked as completed so it will be easy to see what events are yet to be completed. To make this achievement a little quicker try and choose locations for the road trip that are nearby one another so you'll spend less time traveling in road trips. Also smashing all the fast travel reward boards will allow you to fast travel for free to each event.