To all with the vibration problem:

I find this a little mind boggling but I'll post anyhow. I criss-crossed BOTH pairs of my tires (Yokohama Avid Touring
S-rated tires). I took the car out for a ride and there is
only a slight vibration present now (very slight). It's incredibly less then before the swap.

Used to be back in the '80's that radial tires could NOT be criss-crossed due to a possiblity of a blow out. I researched a little because of that and it appears to be
OK now
http://www.roadandtrack.com/technical/articledisplay.asp?articleid=269

I don't think I'll be buying Yoko's next time but for now the car is tolerable to drive at higher speeds.

If this does or doesn't fix your problem, I, as well as others I'm sure, would be interested in hearing the results. I don't know if this will "fix" all your vibration but if you try it, it'll only cost you some time. I also suggest you try it one pair at a time.
GOOD LUCK!