Like the title says, is it possible to interface the oem steering wheel audio control to an aftermarket head unit and make them work?

absolutely. Depending on the head deck you're looking at, check out the PAC SWI-PS or SWI-JACK (or SWI-X). For example, if you're looking at a Sony or Pioneer deck, here's your solution... http://www.amazon.com/PAC-SWI-PS-Pio...ecc_rvi_cart_1

I've used a few of the PAC products mentioned above....works great.

The PAC interface works like a charm. I'm using it right now with an aftermarket deck.