To the Victor...
Place 1st in an Online Playlist match with 11 human opponents
The hardest trophy in the game. Finding a 12 player match can be hard on some modes but the one mode that always seems to have 11 other players in is the Nationals playlist. There are some really good players on this game but it is most definitely possible to claim this one without boosting. If you try and dont succeed try the boosting thread here. The least used mode on the playlist seems to be Off-Road Mayhem so if you and your partners link up in the same lobby then the trophy will be yours.

Endurance
Complete 25 Online Playlist matches
This will come over time. Be sure not to leave matches when the win is too far out of reach and this trophy will come faster than you think. If youre good enough it can be paired with the Long Live the King trophy where you need to win 25 online playlist matches.

Long Live the King
Place 1st in 25 Online Playlist matches
Simply choose the mode that youre best at, for example, mine was Off-Road Mayhem because of the uneven Omnicross events where you could bulldoze through the MX and ATV riders, and win 25 of them. To keep track of the number of events won go to the main menu, and then enter the MotoCard section and select Trophies. Scroll through, locate the Long Live the King trophy and next to it you will see a number out of 25 that you have completed.