whine from engine, intermitten howl from under car, sound from rear end

MILEAGE IS IN KMS! I bought this vehicle used and most of the warranty is gone. There is a whine from the engine which the dealer says is normal...is it? There intermitted low howl from under the seats which can be heard in motion or at idle, dealer tightened all exhaust connections an pressure washed the baffles. They say they can not detect a noise. A thud, thud sound comes from the rear end of vehicle between 60kms and 100km/h. I jacked up rear end and checked for broken tire belts(there were none), checked the bearings, no noise, however the rotor does contact the brake shoe and stops the spin of the tire at one point. Could this be the cause?