Anybody use one of these to direct connect an Ipod or similar?

PIE Converter

I have similar on my aftermarket radios. I suspect that my new car has one, but I can't figure out how to switch to that input.

I used something similar (a third party protocol converter thingy) to plug a non-GM CD changer (a 6 disk unit, I think) into a 1998 GMC Suburban which only supported the GM/Delco expensive/sucky changer.

Worked fine, although doing anything behind a dashboard is a pain in the a$$.