I think Morgan are getting pretty close too with the Aero 8 GT - I'd be surprised if they are legal. Much too dangerous for any pedestrian impact, fine on the race track.
Top Gear last Sunday featured a Camero with similar aero fittings and much play was made of the fact that it couldn't be sold in Europe with such fins.
BUT a couple of versions of the Mercedes AMG A45 have them, so it must be down to size, material or fragility.
Mind you, the lower blade on all Aeros has never been very pedestrian friendly, so perhaps it is all to do with when the basic body shell was homologated.