Place to put reciever thing

i have the original radio and alot of original no.s matching stuff in my car but of course i want and after market stereo i have the speaker strategically placed and such but im not sure where i should should out the cd player reciever thing where i can get to it but where it will be almost unnoticeable, any help guys?

Glovebox?

Under a seat (Only if it has a wireless remote)?

Center Concole?

No center councole 1970 auto with the shifting thing (lol) in the middle.