[multimediaman]

well, it almost looks like you're making an air intake on the side of a car...

possibly the easiest way to go about making that would be to just create the geometry around the intake with edge segments going around the edges of the intake. then select the faces where the intake is and extrude them inwards. now take the face where the intake goes inside the vehicle and extrude that inwards. make sure that extrusion doesn't poke through the car's exterior... if it does, just move the vertices around until it doesn't, and you're set

-edit-

if you don't want to rebuild too much, the easiest way to get the shape like that would be to delete the faces on the interior of the edges you've circled, then shift-clone an edge there, weld the vertices, then take the edge loop around the intake's opening and shift-clone that inwards, fixing any mesh intersection as previously described