yes
gamma/beta radio fits in one slot, then in dash cd changer sits in the other slot.
from what i remember though, in dash cd changers were expensive, going for more than a reasonable halfords special head unit (i.e £60 for just the changer). boot changers seemed to be going for prettty cheep though, if your going to use a boot changer, you can get pockets that go in the gap for pretty cheep.