Mine is just like that half fender. I purposely cut it because one time when i hit 142 on the way to valencia, the fender lining came back and burned itself into the tires. I cut it so that it would be even instead of whatever it looked like all messed up.

i've been rolling like that ever since (which has been a while) with no problems. Just clean the air filter more than normal and you're fine. if you have concerns, you can also put a shield around the CAI filter itself.