I think smell comes from tires not from engine.
I have the same problem on my 2010 Sr5, burnt rubber smell coming from the right rear wheel well only. I also have a vibration coming from the same area (the right rear tire). Can anyone tell me what this might be? I have only noticed this after the first service.
In the summer I get something similar off my 2004 still ! I have always suspected a rubber bracket that the exhaust hangs off at the rear, which likely gets hot from the exhaust and gives a burning rubber odor.
I believe they ship from Japan with Cosmoline (sp) on certain engine parts, this is probably the smell burning off the engine parts.
Just my .02