I do not have the JBL system in my 4Runner, just the basic system.
The radio came in today, so after work tomorrow I'm going to head back to the shop, get out the service manuals to get the dash apart, and see if it works. I'm keeping my fingers crossed.
Everything seems to look the same. Like mentioned above, I'm only worried about my steering wheel controls working. The other bad part is the cost of Scion's XM receiver. The radio was the cheap part. Now, I'm going to have to buy the receiver and antenna made for the Scion radio, which is not the same as the other aftermarket Pioneer receiver's out there (Thanks, Toyota!) I'm not sure whether my parts department can get Scion accessories since I live in Illinois, but I'm going to talk to the rep tomorrow and see if he can just give me the part numbers I need and then just punch it in on the computer. The cheapest I've seen it so far for someone off the street is $488.00!
Anyway, I'll keep you guys posted as to how it turns out. If it works, this will be a sweet (but expensive) way to put XM in your 4Runner and have it completely stock looking without FM modulation.
Grant