I'm not sure if this is possible, but is there a way to buy an OEM Toyota Nav System and install it into an existing '05 4Runner Limited with the JBL 10 speaker/6-disc setup? If not, I guess I'll have to go the Garmin Route until I replace this 4Runner (in about 5 or 6 years!). I was stupid and jumped on a cash back deal on my '05 instead of waiting for an '06 with Nav. Now I'm kicking myself.