Hankook Ventus V2 directional tires on my Jaguar X-Type. Lasted 20K miles, the last 10K of which were shaking beyond belief. One finally developed a large sidewall bulge, and I installed Michelin's, which have been fine for the last 60K miles. I did not think tires could be so horrible, but come to find out, it is possible. Upon removal, it was pretty clear that all 4 tires had various pockets of air under the tread, causing the shake.
I've got to give them credit, without careful inspection, the tires looked fine, despite the horrible shaking.