AC Delco, OEM wiring harness adapter ??

I recently bought an AC Delco,AM/FM/CD/Cassette Stereo Radio (OEM) from a reputable electronics dealer from N.J. for my wife's 93 Seville, 4.9 L. Her car came with the standard AC Delco, AM/FM/Cassette Stereo Radio. I bought the new unit through EBay. The face plates are identical in design except for the addition of the CD player. The new unit came from a 1995 Cadillac (doesn't say which model).

The problem is the wiring harness. My 93 Seville harness has 2 flat plugs while the newer unit has 2 plugs more "box style" same number of wires (except that the CD radio has one more than the cassette radio).

Are there any sorts of harness plug adapters for such a problem? Obviously, I should have removed the existing radio and looked at the harness plugs before buying the CD unit. Any advice would be appreciated.