Play sound from Rear Entertainment System VIDEO mode on speakers

if anyone else reads this thread now (March 2014) note that this has been an issue going all the way back to MY2004 at least. I have spent hours researching this, including on these forums, plus got stonewalled by Toyota Customer Service on a possible workaround and still not good. Appears to me that AS DESIGNED, the RCA AUX inputs in left rear panel only output to headphones, either through the jacks on either side of the rear overhead DVD or audio unit, or through OEM system wireless headphones (or equivalent substitute). DVD player is designed to output through speakers using head unit AUX input selection, but not the auxiliary RCAs in the rear panel. Neither the remote nor the rear entertainment panel controls allow an override to route the RCAs to speakers instead of head unit or speakers. Functionally, this design apparently allows someone to listen to an auxiliary audio or view auxiliary video wired to the RCAs on the rear entertainment system, while the vehicle speakers output another source, but the inability to CHOSE to output the RCAs to the speakers is a royal pain. I installed a simple local wifi in my MY2004 Sienna XLE to allow wireless AirPlay streaming (much better than BlueTooth) of iPhone or iPad audio, but failed to get past the headphone limitation, which defeated most of the benefit. I have a 2004 w/JBL + Rear DVD, which has no AUX 1/8" mini on the front panel, so I'm into aftermarket options. If anyone has successfully rewired the RCAs to feed through the bus to the front unit like the DVD player does, I would LOVE to know. Or, at least (2) figured out the pinouts for the older head unit to SIMPLY add an AUX minijack when the OEM unit didn't have that circuit board, I'd love to know (aftermarket solutions start at $65 and go up from there). Later MYs at least have the AUX mini up front to play with (like this thread), but not 2004 back.