I was under the car changing the oil yesterday and noticed that I'm missing all 3 of the bolts that hold the portion of the front clip that curves upward and makes the front side of the air tunnel to the radiator. Would anyone happen to know what size those bolts are so I can replace them?

 

I don't know the size offhand, but those aren't bolts. That piece is held with large plastic plug things, like those in other places like your plastic fenders and such. The ones under there should be about 1.5" long, with a "washer" under the head that's about 3/4" diameter. You can find them at an auto parts place.

Dave

 

I call em push clips.
They are plastic and have a center piece that once the clip is in you push the center piece in and it locks the clip in place.
Any auto parts store will have these in there fastener section.