I don't know if its possible to do with the REC. There was a company that was modding the RB1 (99-04 NAV units) to do this. I will see if I still have the link, no guarantee though. It was fairly pricey I know that and you still had to have an external player.
[SIZE="1"]2008 WK Overland HEMI - Modern Blue Pearlcoat
Fully loaded with slush mats of course.
MUST GO! 1994 Limited ZJ 5.2L V8 - Light Driftwood Satin Glow
It's a 94 5.2L Limited - trxus 33's on 15x7 steelies, 4.56s w/ front OX and rear trutrac, NP242 swap, novak shift kit, Kevin's ultimate 4.5" lift + ACOS, ARB front bumper w/warn M8000, rear tomkin machine bumper w/ tire carrier, kevin's hardore railz, kevin's ultimate tc skid, kevin's trackbar conversion, rusty's gas skid, flexalite efan, Kolak's performance ignition and brake upgrades. ViAir OBA, custom storage/sub box and I'm sure there's a bunch of other things I'm missing. Everything is a little over 3 years old with less than 10K miles. Looking to get around $4k.
i am very surprised that after 3 years of the REC in 3 different manufacturers' product lines, no one has discovered a hack yet. in my friends 2003 Caddy CTS, it is as simple as holding down two buttons at the same time.