My car has zero provisions for this feature. I've got the typi-fugly 90-95 or whatever the hell year it ended airbag wheel and an old aftermarket deck. Is it reasonably possible to find myself a new steering wheel with controls as well as all the means to connect it to a newer aftermarket deck that supports this feature? What's involved?

 

You would have to find a radio control steering wheel, column, and radio that supports it. These do pop up on Ebay from time to time. If you want to go aftermarket you will have to do some research. I know Sony and Alpine used to have little controls that mounted on your steering wheel and either worked via a wire or via infra-red.