Why not just buy some portable bluetooth speakers and play from your phone? No need to install a sound system in any car these days.
But Otto, that doesn't really give him what he seems to be asking for.
Guitplayer,
Maybe you could try something like this
Single DIN radio mount with compartment???
Nothing I found in searching gives actual dimensions, so really hard to guestimate what may or may not work.
Maybe worth the small price to get one and try it out?
Do you have an "audio specialty shop" somewhere around you??? They might have a suggestion or two.
Dan
