That's what I did, and that's what got my car broken into. Unfortunately, they couldn't get the stereo out of the dash and ended up bending the stereo frame and cracking the faceplate support, rendering the unit useless. And no, the faceplate wasn't in the car, they can get replacement faceplates easily enough that it doesn't matter. $300 stereo, $150 window, 1 day off work to go to the junkyard for a used window and install the window (and just my luck it was raining), $50 for the console plastic and cupholder they ripped out.
So I put the stock radio back in and wired the AUX port for an iPod. $30 for the DIN plug, wires, jack, a switch to enable the AUX port... and the security of knowing that thieves won't see anything worth breaking in for.
I just picked up a '99 SUS, and am looking to wire the iPod to the AUX port. I happened to be in CC today and saw a bunch of random harness adapters, and was looking to see if anything might fit the AUX port. Yeah, I know I can buy two molex adapters, but if there's an adapter that might be close I'll give it a try. Just looking at the pictures by dpdemay to check the sizing of the port.