I would be curious about the DVD bypass as well for a 2007 GS.
I have a 2007 GSh and the navigation "temporary" bypass does not work (it's been removed from the new Navigation discs). Based on posts here and here, it is possible to create a new Nav DVD that brings back the override function. Thus far I've been about 90% successful -- can now enter Nav instructions on the fly, but the touch screen has become really sluggish ((<5 sec delay between press and action). I'm guessing it doesn't like the brand of DVD I used, so am going to try a different one...
The brand I use is Verbatim DVD+R DL 100% success rate