Ya gotta rotate them more often, and quit taking corners on 2 wheels ;-) .

I had a small car that would sound like a helicopter taking off when it got
rolling.  The rear tires wore strangely because there was no weight in the
back, and they would drift on curves.  The lugs on the tire all had a slope to
them, kind of like looking at a saw blade from the side.  These weird facets
would strike the pavement flat instead of rolling, so each tread lug would make a
little 'slap' when it hit the pavement.  Add all that up , throw in some
harmonics, and it's a racket.

You should also check for slipped belts or bad bearings, too.

Bill Marshall
85 GL Tiico "Pandora's Box"
Aurora, IL