I can't see why there would be a change in the drainplug head size/type from 2003-2007. My CVT drain plug uses a standard 19mm shallow socket or 19mm open/box-end wrench. It's a bolt head.
I haven't done the transfer case yet...maybe that requires the allen/hex wrench type of tool. My rear differential required a 10mm allen wrench (or hex socket) for both fill and drain plugs.
The CVT drain plug is easy to see and get to. Maybe just take a 19mm wrench and reach in and see if it fits.
