because they were ruled as properly legit and the rules clearly state body work max not flex more than 5mm.Teams were very quick in 2009 to copy the Brawn rear diffuser.
They were quick to copy McLaren's F-Duct in 2010.
But for some reason, the flexi-wings have got teams stumped.
everyone assumed because its clearly against the rules it would be a waste of time spending money on it.
FIA show they are a bunch of muppets who dont care about enforcing what the rule book actually says.
DD was a loophole, f-duct was clearly legal and very clever, 5mm flex is blatantly not allowed in the rules.
the test is flawed they could stick a sensor on the RB during a test session if they really wanted to keep to the rule book but instead they use an outdated test that makes no sense in a modern world when we have technology they can easily see if it bends 5mm under racing conditions