Brett
You don't need to purchase ANY type of DIN adapter for your 89. This is what I did to make it look like this:
Here is a list of parts you will need:
1. 1/4" trip piece (available at any Best Buy installation bay or Circuit City)
2. appropriate harness (avaialable at same place make sure you tell them you want to bypass the stock amp if you want your Blaupunkt to power your speakers instead of the Ford amp)
What you do is first remove the ********* piece that goes around your whole radio. This is the same big piece that houses your antenna up/down switch. There is one bolt underneath the setup you have to remove before pulling the whole piece out. After you remove that bolt, there are a few clips that is still holding it in place. Just pulll it and it will come off.
Next you remove your stock radio and put nothing in its place. Now what you do is front load your aftermarket radio onto that removed place piece. You basically attach it with the metal cage to that black piece with the trim piece sitting after the black piece and before the radio.
It will go in this order:
:

ASH::BLACK PIECE::BLACK 1/4" TRIM PIECE::METAL CAGE THAT HOLDS RADIO::RADIO::
When you are done re-attach the black piece (that has your cd player attached to it) back into the dash and you now have a front loaded cd player that fits as flush as possible with your dash.
If you have any questions just PM me.