ICE is the best solution folks, even if you have a low budget, dynamat the whole car including roof, doors, trunk everything!
play some good music, that way you cant hear the annoying honker.
also get the darkest tint possible, yes you will have trouble driving at night but when you give your 'im gonna cut your throat' look at the other driver who cut you off, he dosent see you
keep the ac on ice cold blast too.