Its hard to say. It could be your rear brakes rubbing against rust
on the rotors. Or tire noise. Or worn hub bearings.
have a 2003 hyundai elantrs, lately when i drive my car if i
> go over 2o mph it sounds like my rear wheels or rear axle is
> making a whirling sound - the faster i go the louder and
> faster it gets (almost like a jet engine). it is winter and it
> has been snowing a lot - is this something to worry about or
> will it go away?