when I go 80 n up it gives me a very annoying buzzer , how could I turn it off ?

The 2013 has an "engine immobilizer" feature. I am going to say that the buzzer you hear is warning you that if you go any faster the engine will shut off. This is so you can't try to out run the cops. I have heard of other vehicles with the shut down feature. You had to buy an upgrade chip to bypass the vehicle shut down. I did read up on the immobilizer but nothing is mentioned in the manual that the engine will shut down during excessive speeds. I'm just guessing. You can always push it higher to see if in fact the engine will shut down. I haven't been able to find any real info on the issue you are experiencing..........Try ToyotaNation.com