I'm interested in the AMG spoiler as that look is personally appealing (although I've had respondents to other posts elsewhere provide other opinions). Styria, I will look for your post elsewhere but perhaps a pointer to the topic heading to make my search easier?
BAR, to your question, you raise an interesting one. Several points: the US-spec bumpers were mandated by the US Dept of Transportation (DOT) for the manufacturers of vehicles as a response to insurance company lobbyists in the '70s. The bumpers were designed to withstand a 5mph bump without creating damage to the vehicle. Having said that, vehicle owners can do whatever they want to their own vehicles. There's even an industry associated known as SEMA (Specialty Equipment Manufacturers Association) that lobbies lawmakers on behalf of enthusiasts so that owners can modify their vehicles with aftermarket parts and accessories (currently a multi billion dollar business). The US system of government is amazing isn't it? For every industry lobby, there's a counter-lobby.
As for me, I just like the way it looks so I'll do whatever I damn please. Besides, I'm a lawyer.