So like what I figure most owners have, I had this radio:
I wanted to upgrade it and get an aftermarket one in there. I didn't want to spend a lot doing it and I also didn't want to wait for someone to put out an aftermarket kit. I ended up having to choose waiting or spending a good bit.
After talking with Crutchfield, Best Buy, Metra and the dealer, I ended up buying all the parts to install the aftermarket radio, ironically, from my local Mitsubishi dealer. I was linked on here to a page to buy it direct from China, but the part looked less-than-ideal, and the included brackets were plastic. In addition, it'd take around 2+ weeks to get the stuff from China, and only 2 days from my dealer.
I got a front panel and 2 metal brackets from my dealer, total cost out the door was about $90 including tax ($80 for the panel, $10 for the brackets). It's not the prettiest install, but I'd recommend it for anyone that wants to put an aftermarket system in their Mirage. When the stuff for my amp comes next week I'll post a guide on how to do everything with links and model numbers for all the important stuff.
If you want to go ahead and order the parts so you can get cracking as soon as I post the guide (or to do it yourself beforehand, knowing you likely have the correct parts), here are the part numbers:
Front Panel: 8002B480XA
Brackets: 8750A262, 8750A263