There is a Flash Media Server at this url
. Looks like it's meant to respond to a call to remote procedure "mediaplayer.getAudioInfo" with ID of the audio sample provided as argument. Structure it returns might contain URL to the audio sample. Although, this could also be set up in a way that won't actually expose URLs, but rather streams audio directly.
Unfortunately, my Flash skills are rudimentary, and I don't happen to have a compiler sitting handy. I tried to poke around the gateway directly, but it looks like any tool to actually extract the info you're looking for will have to be written in Flash. Mind, that's even if it allows access from arbitrary domain in the first place. (Although, I have had no trouble getting basic "service is running" response from it.)
Here are snippets of relevant ActionScript in case someone wants to take this further.
this.gw = new NetConnection();
_loc1_ = new Responder(this.parseAudioInfo,this.onStatus);
Memory.params.id contains the ID of the audio sample you can find on the Advertising Council page. Might be as simple as dropping this into a bit of Flash code to get all the info you need.
And if anyone wants to poke around with a decompiler a bit more, this is a direct link to SWF of the player
. It can be downloaded and decompiled to poke around the ActionScript that runs the thing. Most of the fun stuff is under scripts/com/rockstargames/mediaplayer and the audio info is retrieved in the data/ContentManager script from the above.