My 2000 Hyundai Sonata came with this H935 stereo unit:
http://www.hyundaiautonet.com/English/Before/product_view.jsp?pno=58#

It supposedly has a CD changer. I have not been able to figure
out how to load the changer, which would be a vertical stack of
slots that hold each CD at the edges. I am able to play one CD at
at time, but no more.
I've reviewed the instructions in the car's manual, which doesn't
cover these procedures, yet the unit has controls for changing
the disks. Also, as a radio of "Double DIN" height, it appears
that it might have enough room to hold a 6-disk stack.

I have had a home unit of similar profile apart for servicing; it
is loaded through the same slot in which single disks are
placed -- the machine swallows them one-at-a-time (until it
breaks). It goes through worrysome gyrations in which it moves
things out of the way in order to load, retrieve, and regurgitate
the CDs; and then back in place in order to play them. Frankly,
I'm amazed that these mechanisms are able to last at all.

Is this contraption really a CD changer, or, are the controls
that I see only to run a CD changer that's kept elsewhere, such
as in the trunk?

Richard