When i was working for Toyota as an service advisor last year (or so)i was told by my workshop chief mechanic Rav 4's were notorious for road noise,Every Rav that came in i personally drove to find if this the case as I was in the market to buy one & wanted to find out any discrepencies with these type of cars (small all wheel drive suv's). Differential noise have never been the case but to eliminate this I had recommended & used a differential additives from Redline & Penrite oils,on the next service some of my customers but some came back & still complained about persisting 'road noise' After the initial check over (shockie check,wheel bearings etc which I perosnally involved myself in) I can say a majority of Rav's have noisey tyres (apperently its the wheel base geometry combined with the low factory height) & this is worsened by deep tread 4WD tyres that arent factory endorsed. Very rarely are bearings & shocks at fault,as bearings on the newer Rav's are one piece units now & theyre made to be 'unservicable', as for shockies on a 2005 youre shocks should be just coming outta puberty unless your constantly go bush bashing,pull heavy loads ,city terrain should not wear shocks but worn shocks shouldve been picked up on the pre service check ups.either by oil leaking (drip or weeping) regrettably this can be missed by technicians. Bring this up with Toyota,Your car's still in warranty so get the shocks changed over first then get them to do a undercarriage check again,maybe have you or your wife present with the technician/manager when you drive the car (before n after service)this covers u if the whirring occurs & having them there makes your case valid. Good luck