Be better off not mounting it to the seat at all...its gonna shake like a mo fo w/o anyone in the seat...
Take out the grill & mount it in there(or in the bumper)...can't possibly catch too many bugs in the quarter mi & it would make for some cool vids

Make some kind of mesh to fit around it so you don't really notice it....
Hell, it would be cool for the street if it weren't for the bugs...(plexiglass??)