I too have OEM splitters. Fitment is amazing. They can be had for ~560 (?) iirc from golfrrr's parts dept.
Look for used ones in the classifieds section. They come up quite often.
2011.5 E90 Dinan M3, SS II, M-DCT, EDC, M Drive. Winter setup 220M w/ 255/275 Blizzaks
Performance Mods: Dinan St.1 suspension, exhaust, intake; TTPs; BPM St.II, DCT, servo tunes
Cosmetic Mods: OEM CF splitters, mirrors, center console, spoiler; Arkym CF diffuser; LUX; tint