This is a known issue with the Toyota Rav4. I took our Rav in and they tried telling me it was a poor speaker connection. The thing they did not know is that I had done my homework and knew the head unit was the issue. So I asked them, if it was the speaker then I should be able to balance the sound to the opposite side and not hear any static. They agreed. So I did and took one of the guys for a ride. To there surprise the noise was still there. They then said it was the antenna cable. I told them it was a head unit issue, but they had to do it there way. So they replaced the antenna and a cable to the head unit.. The noise was still there as I expected. Next they replaced the head unit and the noise has gone away. I have had the new head unit in for 5 months and no more noise. One of the techs admitted quietly they new the head unit was the issue. They just hate replacing so many of them. Be persistent that they change your head unit and tell them you know it is the issue even though there is not a TSB yet. Hope this helps.
