Here's a couple pics of the install I did last summer. 6.5'' Component speakers in the doors, Metra 99-5826CH Dash Adaptor, Aftermarket HU, 10'' Sub and 2 amps.
There's still more than enough trunk space for me. Install was fairly easy. The Wire Harness for the HeadUnit was an AXXESS FRST I believe. It retains SYNC and steering wheel controls. I also think the wire harness works with any aftermarket HeadUnit. The HeadUnit is the easiest part of the install. The wire harness just plug clips into all your factory clips. It's just plug and play. Only thing you have to do is butt connect or solder a few wires for your new HeadUnit.
2011 Kona Blue MT82 V6 Mustang Pony Package 3:31 Gear Ratio, Interior Upgrade Pkg, Security & Shaker500/Sync
Mods (in order of installed): AM Bama SCT SF3 Tuner w/ 87 Hybrid Tune, Airaid CAI, Hurst Billet Plus 2 Short Throw Shifter, Lethal O/R H Pipe w/ Stock Exhaust, Blacked-Out Tints on Rear Windows, Full Ceramic Tint on Front Windows, Metra Touchscreen Dash Adaptor, Single DIN Head Unit, 6.5'' Component Speakers Fronts, Stock Rear Speakers, 10'' Sealed Subwoofer, 4ch. and 1ch Amplifier. LED licence plate lights, LED interior dome lights, FRPP/Dynamic shocks and struts, SR Performance lowering springs, GT500 Strut Mounts, BMR Adjustable Panhard Bar, BMR LCA's, BMR Relocation Brackets. Rear Seat Delete.