Yeah, this has been discussed in the "Installation Notes" forum recently. The Honda slot is slightly smaller than double-din. But there were pictures of others who had managed to cram an Empeg and a DIN stereo in there by removing the plastic spacer bezel from the DIN stereo. You'd have to be very careful of everything you did and do a lot of fiddling and test-fitting (with the dash dismantled and the mounting cage removed). But I think it can be done.

Have a search through the Installation Notes forum for "honda" and see what you come up with.