At speeds of 65mph or higher my steering wheel shakes a little left to right. Just enough to annoy you on a long trip. The dealer checked it out, replaced both rear tires, (said they were not balanceable). Still have the problem. Dealer checked it again, aligned it. Still have the issue. Service manager said the car meets all specs in regard to alignment issues. He said the CTS-V is supposed to drive this way due to it's high performance suspension. Anyone else experiencing this? I have a hard time believing a $50K car doesn't drive as good as my $25K Grand Cherokee on the highway.