One of these joined me on a 50mph limited Dual Carriageway - as it accelerated sedately up to the signed limit, a rear spoiler popped up from behind the back window - what, if anything, is it for ? Surely this car is FWD so any downforce generated by the spoiler will be on the undriven wheels - so a pointless pretentious thing or an useful extra ?
At 56mph it will be useless - at 120mph when the driver lifts off going too fast into a long bend it might just stop him going bum-first to his/her doom.