I'd need to see the back of the stereo as it might look like ISO but some of the GM/Vaux stuff was a 3 block ISO which complicated things.

Also being a GM/Vaux the standard stereo cage holds the blocks in place so you have to piss about with the removing the cage to get it all to fit properly. Good news is there's loads of room below the stereo to hide all the cabling - from memory. I think the ashtray comes out quite easily, 2 x torx screws.

All easy enough to do just need to take it apart and understand what's going on.