I suspect that the part you are trying to open is not the part that contains the air filter. Attached to the engine air intake is teh air duct; this duct leads to a plastic box attached to the radiator core suppoert up near the hood area; I believe this may be teh part you are trying to open, but this is NOT the air cleaner housing. You ahve to remove teh 2 bolts that hold this box (a resonator chamber) from the core support; you will find there is a second air duct coming out of the bottom of the resonator chamber that leads downward, and teh other end of this second air duct is connected to the air filter box. Once you have removes the resonator box and teh 2 air ducts, you will see the air filter box located way down towards teh bottom of the radiator core support area. This box has a lid that is held on by 2 spring clips; release the clips and the lid will lift off revealing the air filter inside.