No problem
If you download the free burning program ImgBurn, the Layer Break is in the menu: Tools, Settings, Write, Layer Break (set to 'User Specified', 'Sectors in L0' set to 1261456).
I don't know how to do it in any other program, but if you follow the steps in ImgBurn, it's not too hard.
Ah ok, I had read that all of the Rs (50 or so limited edition models) had DVD playing capable head units. But that's based on Specs from eg Carsales and Brochures/Magazines. And it's only roumored to be version C2 for those few cars. So if you want to try C1 first, that is the version for all other Libs except *maybe* the Rs. So basically all other Gen4s use C1. Not sure if the build month makes a difference. The slightly different head unit in the R would at least explain why it'd be C2, but let us know.
Yeah, the sound system is the 14 Speaker McIntosh that the GTSpecBs like mine got as well - I like it, even if the wagon version lacks a bit of bass.