I think generally we're just afraid to cut into our cars and deal with the hassle of hoses etc. I'm guilty too, I have the STR40 kit instead of going with my first instinct to put ducts on the car because it's just easier and cleaner. But...
Sadly it's just physics y'all. Even if like me you've put a bigger better pump on the car when you put better bigger rotors on the front, it's dead-heading with nothing but turbulent hot air to throw out from the upright without ducting. Even just using the front airdam hole to get some throughput of cold air into the wheel well would help. This is what the stock ducts on other BMW's and many other performance cars do, but for some reason M division has decided its cars are special and exempt from the laws of thermodynamics and/or they decided beginning in about 2005 that they don't care that the cars can't stand up to extended tracking with just a pad change (obviously the latter...M is for marketing)
Get you some ducts, get happy, if it were me I'd do some testing to see if just running a hose and pointing it at the upright from the fender liner might be sufficient for most tracks with race pads
Still wish somebody would make a control-arm mounted polyurethane/frp scoop a'la porsche for our cars. Seems like it'd be a fun cad 3D printer project. Hell at $15 plus shipping I'm tempted to try and make these work:
https://www.ecstuning.com/Porsche-20...ing/ES2526435/
THe porsche front LCA and ours isn't that dissimilar in angle/purpose