Tire Problems

[fullthrottle52]

Hello to all,

I have a 2000 base that I purchased in May of this year. Have really enjoyed the car so far. Chased a CEL light issue for the first 2 month but finally replaced the MAF sensor and all is good. In August I decided new tires were needed. It had Michelin Pilots and ran very smooth but tread was thin. I purchased a set of Hankook V12's from Discount Tire on Line. Had them shipped to my Indy and he mounted and balanced them. I had a bad shake after the car sat overnight. Once they warmed up the shake would go away. Temperature didn't seem to make a difference. Hot or cold morning it still would shake for the first 5 to 10 miles. I felt it in my rear end more than the stearing wheel so I thought I had a bad rear tire. I took them back to the indy and he rebalanced the tires. Same issue. Once they got warmed up the shake would disapear and tires ran real smooth. I called Discount tire and they suggested I replace the driver rear tire and see if that helps. I put a new tire on the driver rear to no avail. Same issue.
Obviously I have thought the tires an getting flat spots from sitting. The unsual thing here is that the car can set for 4 to 5 hours at work and i get in and go and don't have the morning shakes. I'm toldy by my Indy that flat spots don't ususally happen from overnight sitting. Maybe if it sat for a couple of weeks but not overnight. So, I took to a local tire store and had them road force balanced. I watched as they balanced them and they were spot on. I then take the car out for a spin and get a bad steeing wheel vibration at all speeds but worse at 70 to 75 mph, right where you want to cruise on the highway. I am ready to give up. You have now heard my winning story, but I really am looking for someone who may have had a similiar situation. Is it somthing mechanical that is causing the bad vibration in the morning. The car is stored overnight in a non heated garage with a cement floor.

Any help would be appreciated.