I know that car (that's my photos), so can answer any questions.
The "opening to the front" is unbroken. Yes, inner thin-plastic frame is modified. It was not very easy cause originally that car was equipped with the smallest stock display. The navigation-version-frame is closer to 7in result (GM 62 36 652). Also the embergency light button is modified for lower the "floor" of frame. Stock monitor is remounted to the seiling and CAN-wires was extended without any problems.
There is an idea (if you need larger display) to use plastic cap from zafira. It is similar design and place for central channel for 5.1
Hereis the ways for different monitor implantation:
1. Stock yellow-black - is suitable only in trashbin.
2. 6,5 800x480 - very difficult to find/compose but fits the stock navi-frame of $10
3. 7' 800x480 - most popular carputer formfactor, but required some works on dash fabrication.
4. 8,4 800x600 - most quality native-resolutioned monitor, require serious fabrication work.
?Does anybody see 6,5 bright lcd-touch 800x480 142x79mm? I've found sharp and auo, but there is not datasheets for auo. Infill's display is not acceptable for quality reasons.
DeadReconing forever! testing in progress. (tyco)