I installed a Jensen VM9512 - single DIN, pop-up 7" screen, GPS/DVD/5.1 surround/hands-free BT; 3 camera inputs, SD card slot front; USB input, etc. With over 40 wires out the back it turned into a major headache to get it all the way into the bucket. I had to cut away material from the rear of the bucket inside, but it didn't gain much. Left the VMM alone (find it vey handy). There might not be as much room there as you think...
In the end, for me the Jensen was worth all the trouble as I gained radio, hands-free phone, camera(s) display and GPS without having warts hung on the dash. Key off and it all retracts into the headunit. Phone, GPS voice nav, radio audio, all still works when retracted, as well.
In theory, you could leave the stock radio and make similar gains using a front/rear windshield mounted dash cam up by the mirror & leverage a smartphone w/hard-wired~FM transmit hand's free bluetooth (calls and and music) and a HUD display for nav. Sit your phone on the HUD, auto connect via BT to the head unit and go.