The problem with the Google drivers is not so much the address, but it is google's policy on direct access to the servers that serve the tiles. Through an internet application, it is easy, just type in the address of a tile, and it works. Google has some smarts on the server end when something other than a browser trys to access the tiles, and it gives an error, something along the lines that it thinks you could be a virus or spyware trying to access google, try again later.
I have no idea how google does this, but I assume that any httpWebRequest is tagged with some application info that has sent it. Google must intercept this on the server, check it out, then return a response based on whether it falls into their accepatable users category. I don't know if there are ways to cheat this, i would assume so, but I can't say.
If I figure this out I will let people know.