I used an Irock for a long time and loved it (with a cheapo RCA Lyra MP3 player). I then got a new Panasonic head unit when my crappy Chrysler one wore out, had a cable out mounted through my TJ's glovebox, and put tiny strips of velcro in my never-used ashtray to keep the tiny Lyra from falling out at unusual angles/violent bumps. When not in use, I put the cord in the glovebox and close the ashtray-totally stock look for a $35 on Ebay MP3 player that sounds great (BTW, the Lyra puts sufficient volume out that I can leave my head unit at normal volumes to use it). I use it every day.
Matt