It looks as if the new Far Cry will be letting you do creative with the environment.
According to a video interview with Alex Hutchinson, posted on YouTube, it looks like you will be able to cut the brakes on cars and even plant c4 on elephants. (what a messed up thing). In the video he explains how this will effect gameplay and how the co-op feature will work.
"If you come online, I invite you into my game, all that single-player stuff is still safe, it's still there, but we turn it off while your buddy is there because everyone just skips the cutscenes anyway. You have access to all the crossover stuff - so all the outposts, the fortresses, the belltowers, all the open-world quests that I can complete with you.
"Then when you leave, I go back to my single-player game. And if you're worried - everything can be completely completed in single-player, there's no need to play in co-op, but if you want to, it's always there.