I've elected not to use them due to the airflow they'd take from the cooling system for minimal gains at best. From pictures I've seen, I'm also not a fan of their design and the sharp 90 degree angles that would potentially create turbulence.
2008 AW E88 Auto
BMS BEF (w/Cobb), G5 ISO, SLD, CPS, DCIs, & OCC--
M3 FSB & FCAs--
ER SS brakelines--
Stoptech slotted rotors w/Ferodo pads--
Apex Arc 8s wrapped in Michelin PSS Future upgrades:
Wavetrac LSD TBD: