After reading forums on here and pouring over ebay pictures and ads, I have discovered what I believe to be an easy retrofit.
I have a 2014 mirage with 79,000 miles and the stock radio is acting up, buttons on radio don't work properly. My wife and I have 2020 mirages also. Our mirage's both have stock touch screen radios, but hers has a CD player and mine doesn't. So I figured that these radio's will plug up to old connections, but before forking out $100+ for the radio I thought I'd better read on here some more.
What I discovered in a nutshell is this.
This is the 2014/2015/2017 basic radio
The stock touch screen radio with a CD player that comes in 2017 and newer Mirages, is manufactured by Hyundai, and uses different plug-ins in the back of the radio, consequently there is an adapter harness found in cars with these radios but the harness is next to impossible to find online. These radios usually run for $120 on ebay and LKQ.
Then I wondered about the radio that is in my 2020 mirage that doesn't have the CD player.
Manufacturer Part Number: 8701A753
From all the pictures I have looked at on ebay the plugs are the same as the 2014 radio.
So most of these radios are running $300-550 on ebay, but today I got really lucky and found one on LKQ for $118 shipped, I then ordered the double din radio facia plate on ebay for $27 shipped. I will post results once these parts come in and I confirm that my hunch is right, and that these radios will hook up to the 2014 and 2015 mirages with no extra stuff