Why do you need to cut a hole or something? Take out the CD changer in your glove compartment and utilise the vacant space :top: u r lucky coz I'm driving my E60 today coz normally I drive Hilux to work. Anyway, will show you the picture on where I install the DVD/MP3, CD player (it's Kenwood btw)
From the outside when I open my compartment
Close up - this is where the original CD changer supposed to be! notice the USB device there?? Loads and loads of my fav songs inside! Save the hassle of changing CD as the area is quite hard to reach when driving!
Playlist shown in my iDrive's screen
Movie in my iDrive's screen
This is Garmin gvn53 module unit which was installed underneath (not inside) the compartment on the passenger side
Malsingmap direct on the iDrive's screen
I have also installed Reverse Camera & here is what the iDrive screen show when I put my gear on Reverse
Alternatively, if your CD changer is still working but you want to install DVD player, you can opt to install it here! I have seen one or two car installed it this way! That is, if you are OK for them to cut a hole here 
