Hidden CD Player W/ Retrosound Stereo Recommendations??

[justin_jj_Taylor]

I bought the Retrosound Stereo for my 73 GMC, and it works great but I would like to mount a CD player somewhere hidden (perhaps under the seat)

Is it possible to run a device that only plays CD's (sort of like the old music mans) thru the aux cord that comes out of the stereo? I love the stereo but I miss my CD's. I need something that isn't battery powered and is only on when the truck is on. Has anyone done anything like this before?? I'm not real certain what to look for. Thanks!