Tried searching, but couldn't find any diy on how to install the front grill on an ap2 bumper. I imagine having the bumper off of the car would make it way easier, but is it possible to install it while the bumper is on the car?

 

I couldn't find a way to install mine with the bumper still attached. Bumper removal isn't too difficult, and you can have everything done in ~45 minutes if you take your time. The only thing you might need in preparation is a few extra bumper clips, as they tend to break upon removal. Good luck!