thought I would chime in..I'm new but I do know a thing or two about superchargers since I daily drive a 98' GTP with a modified M90 supercharger with a 3.4 pulley diameter pulley...roughly 8-10psi of boost I believe....I ditched the stock air filter setup because a box filter on any engine for performance is going to be a bottleneck. Sure benz might of done there homework and created a super efficent intake, but its still not going to flow like an open element style. For my GTP I opted for a Thrasher CAI and it works great. On the GTPs you have to worry about KR (knock retard) because the engine senses knock (detonation) and pulls timing away from the engine as to not damage it...with a scan tool hooked up to view the KR, I was getting around 2-3 degrees @ the top of 2nd gear...after installing the CAI I had 0 all the way across the board....maybe on my application it was different but I think you cant go wrong with an open element air filter. Supercharged and turboed engines love as much air as you can give to them...on my 300D I noticed that the stock airbox makes a 90 degree bend...and I was on a forum and heard someone say its not restrictive...lmao the thing is practically kinked in half! Sometimes stock isnt the best. Plus when you put an open element style in you can hear your supercharger or turbo a lot more.....on my 300D it screams...I love the sound! Superchargers make a "wrr" sound but its still intimdating!