Oiled filters are known to be bad for the M5 mafs, AND give almost no better performance.
The entire Dinan CAI, $2500 worth, adds AT MOST 6hp and only then with their software.
Unfortunately MOST OWNERS who oil their fitlers do not realize their MAFs are fouled and drive around with less HP than people running stock paper filters and changing them every other oil change.
IMO of course
Keep it as simple as possible...but no simpler.