Thanks for your guidance .Sorry eilif, but I don't have much of an answer for you.
First, you can pull the head unit from the dash and unplug it. The hazards and such should remain working.
Second, a scrap yard or eBay is your cheapest solution. Obviously buying a new factory head unit isn't cheap. And installing an aftermarket head unit requires some pricey parts (~$225 in parts).
Is the head unit the grey box with two big plugs, one small plug and a CD slot?
I just pulled it out and have it in front of me. It's a DT1T-19C107-AF. Looks like there's lots of similar units on ebay for around 100.
Now that it's out, I won't get any more cackling right?
Are there no aftermarket units that use the stock screen and button interface? I have what I think is the stock 4 speaker with 4.2 LCD screen.
On the plus side, the ease with which I was able to pull this, has me thinking that if necessary I can probably tackle replacing everything with aftermarket.