I have a similar issue in my 2011 Hyundai Genesis Coupe. The static is only present during loud levels on songs, not at all times during the track. Seems like it is most noticeable on the higher frequencies also. Please reply here if your issue is the same.
I did not have this problem on my HTC One X in the same car.
I have searched all over Android and Hyundai forums and found little to work with. What I have found is that this is not affecting everyone, otherwise it would be all over the forums. I appears to me that it is related to our cars bluetooth receivers and how they communicate with the phone.
I found some posts from a user CBaronne where he had what appeared to be the same issue on another phone and modified the "Bitpool" value with good results. He wanted to do the same on this phone but the variable is buried in a system file and modifying it was beyond his expertise.
I have also flashed several sound mods with no success, as well as different tricks to ensure that APT X is enabled. Nothing has helped.
I think until we get a developer with this phone and has this issue there will not be any attempt made to resolve. You can always just buy another car...