Anyone that's done this having issues with brake ducts getting pinched or damaged with full steering lock? My E36 has bimmerworld brake ducts in two sections... one from the front bumper to a flange in the fender liner, and another section that I usually leave disconnected that goes from the fender liner to the backing plate. If I use full steering lock the duct gets pinched or torn so that section is only for the track.
I like those turner inlets, but that's a bit pricey compared to hacking in something generic. Ditto on bimmerworld's $250 (per side) CF backing plates, but at least those aren't just plastic.
BTW, the inlets seen on those racecars are called NACA ducts. It's a shape that was found in aircraft research in the quest to bring air into a flat surface with minimum drag. Pegasus sells generic plastic ones in different sizes for around $20. For that matter they have generic rectangular air inlets for $23.
If you're worried about critters getting in, then it shouldn't be too hard to work in some wire mesh (aka chicken wire :-)