Mystery aero-device on Audi S5?

[SL8Brick]

I was checking out a few S5s on our dealership lot and couldn't help noticing this unusual aluminum-colored thing a the bottom of the rear bumper, between the tailpipes:


It may look small in the photo, but it protrudes a good 3" from the bumper surface. Is this just flashy eye-candy or does it have potential function as a lower level difusor/extension?

[GasSavers_TomO]

My guess would be partial eye candy with a small benefit similar to a diffuser.

[Snax]

My guess is that the rounded profile of the bumper encouraged air to follow it too high up from underneath. The lip encourages immediate seperation.

[lunarhighway]

the devise (and the car) pictured above looks more subtle and stylish than what i'll show below
my kadett (also note the massive pop up whale tail spoiler )

here's another example on a citroen AX






both cars have a very prominent "lip" on the rear bumper... i suppose this is somewhat similar to the lip spoilers found on the rooflines of hatchbacks and sometimes trunklids on sedans... just something to get the air off in the right direction like Snax pointed out... note that the AX has a spoiler like portrusion at the base of the windshield... this was part of the trunklid and all models had this... i believe the cd of the car was around 0.32 wich is pretty good for something build in the 80's... it's interesing as the angle of the windhield would not allow the air to stay attached , but maybe the bump breaks some turbulence going on there. anyway, i just mention it as these are two cars that had a lot of aerodynamic features for the time, so i'm sure these bumps and lips are there for a reason other than looks...

the audi looks great, and is probably much more aerodynamic too, but on todays smooth styled cars it's sometimes hard to tell what's for looks and what's effective

[brucepick]

Yes - I've seen similar on most Lexuses (Lexi??), though in painted plastic.
I think it must be to encourage clean separation.
Or you could call it a mini-mini Kamm back. Same idea either way, I'd think.

[JanGeo]

It may also prevent exhaust fumes from building up around the trunk and may also create a vortex around the pipes. Sure wasn't put there by accident . . . that's for sure!

[DarbyWalters]

Seems like an easy addition to almost any vehicle!

[GasSavers_SD26]

I think it looks cool.