There is no extra open din slot in the car. I have seen a deck shoved where the cubbyhole/cig lighter plug is but that is far from the best place for a radio. I just bought an adapter plate. I got a discount on it when I ordered my deck too. The other way sounds like a large waist of time and it will look horrible if you don't do a good job.
Would there even be enough room to get a CD into the radio with the shifter there?