I see this problem is going back to the '09s and I just bought an '11. REALLY disappointed in the low volume and how Toyota has ignored this. Frankly I think its a flaw since you can't hear it on the freeway without maxing it.
Anyone try a line out dock?
Will the HU amp the source signal its self then if the ipod/iphone isn't?
Any other cheap options if not? i saw the preamps but frankly I don't look forward to turning it on and off and keeping it charged.
Glad I didn't get the JBL upgrade, thought it sounded like crap for the price anyhow!