I had posted this as a reply to another problem and didn't notice.
I think it'* good information that a other unsers might use.
A few days ago I posted a problem with noise under the hood on my 1999 Bonneville SE.
I thought it would be interesting to let everyone know what I found.
To recap, the noise sounded like a heat shield rubbing on the asphalt but it followed the engine RPM and happened ONLY when making a right turn. The noise was proportional to the side G force. I replaced the motor mounts, removed a bunch of shields and nothing seams to make any difference.
It turned out to be the Bendix (starter gear) loose and rubbing on the flywheel when I made a right turn.
How I found out was: I removed the little plastic cover to expose the flywheel, started the engine and rubbed a chalk on the teeth then I when for a ride (before turning the engine off so starting the engine would not rub the chalk off)) and forced the noise for a while.
When I returned I found the chalk was starting to rub off on the edge of the teeth.

I thought I should let everyone know so no one else go crazy trying to figure this one out.