I have seen these things for sale in tuner magazines, and now I started noticing them on the Audi A series sedans and wagons, what are they? Are they just for show or do they actually improve handling somehow?
Yup. Antenna. I think it's powered AM/FM. They're more "aerodynamic" than whips, and better reception than the older window antennas (they look like defroster wires on the top of the rear window)Most likely also GPS / XM capable, depending on the car's options...
2003 Vibe GT Lava"He inched his way up the corridor as if he would rather be yarding his way down it.""For a moment, nothing happened. Then, after a second or so, nothing continued to happen." - Douglas Adams...we all miss you
Looks like a satelite radio and/or GPS antenna. Most likely radio. Maybe they have a regular antenna in them too. They are on all kinds of brands, although they take on different shapes. GM is using XM antennas that look like a short/fat antenna, its only an inch or two above the base, and it is about a quarter inch to a half inch in diameter (rough estimate)