PontiacBonnevilleClub.com

I am getting a wiggle between 40 and 50 mph upon a pretty normal paced acceleration (between 2000 and 2500 rpms). I also get a similar wiggle right around 80 mph.

When a wheel/tire is out of balance, will it have modes where it will get smooth, then bumpy? I am planning to order some new tires at the end of the week, and I am hoping that getting them mounted and balanced should take care of my wiggle that I get.

Any other ideas what could be causing this?

Yes, an out-of-balance tire will be felt at some speeds and not others.

If you are feeling an unrelenting whole-car shimmy in the 65-73 MPH range then you might want to follow this thread where we are trying to narrow down the cause of a common shimmy issue.
viewtopic.php?f=18&t=17296&p=203475#p203475

My mechanic drove my car yesterday and both of my rear tires he believes to have shifted belts. Also, my driver's front tire has a flat spot

That's alright, I have 3 Fuzion HRI's to match my the one good tire that is currently on it. Friday is the day to get them on

A quick update..

So 2 weeks ago, I got all new tires. Fuzion HRi. Great tire, it's pretty cheap for the amount of performance and lack of tread wear according to the ratings on TireRack. Car runs great, tires feel awesome on the highway and at all speeds. Very smooth and minimal road noise. Still have the "shimmy", though. Went to my personal mechanic today and he narrowed it down to my driver's side drive shaft. I knew the CV boot was throwing a little grease, but he informed me that my drive shaft was actually loose on that side. He is really confident that replacing it should take care of my problem. I guess I'll find out later today or tomorrow depending on when he can finish it up!!