Just to confirm, there is no difference in the size of the airbox or filter in a 2003 with an L36 vs a 2004 with an L67, is there? I did a swap shortly after I started driving the car regularly. I notice such a HUGE difference after cleaning the K&N drop in that is in the stock airbox I almost think the car is starved for air. I clean the K&N filter 2-3 times per year, probably every 10-15k miles of highway use. I've seen a lot of info here on replacing airboxes - fender well ideas and the like. Before I go that route I just want to make sure the stock airbox that was in the 2003 isn't too small (to be spec) for the L67. If I do a swap, I'm pretty certain I'm not going to go cutting a hole in the fender well due to water reasons. Here in the NE we get plenty of rain, snow, etc. that could make that a real nightmare.

 

nope the air filter is the exact same between the two motors

 

It is the exact same stock air box between the L36 and L67...but that blower is definitely starving for air. You will see a huge increase in throttle response and overall power with a decent cold air intake or fenderwall intake.