I am about to produce cold air box kits for the e30 M3 that isolates the fresh air charge from the engine compartment. This assembly require no drilling or cutting holes in fenders or frame. It (imho) keeps about 95% of the hotter engine compartment OUT!
The assembly utilizes a KN type performance air filter and a two piece aluminum housing. It includes a black wrinkle finish cover plate and all hardware. It is a bolt in/on unit that will take only 15 to 20 minutes to install.
The unit was tested against an evo air filter assembly and on the chassis dyno and realized a 4.4 to 4.8 HP gain @ 6100 rpm! I have included a link to the dyno chart for your inquiring minds.
The unit is priced at $250.00 + shipping.
Email me if you are a serious M3 enthusiast!