Man, this site has an answer for everything! Been wondering about the rut-wandering ever since I bought my roadster a few months ago. Figured it was the tires, as the idiot dealer put new Kumho summers on the back and left the all-season old Contis in front. The damper makes perfect sense, though.

Just ordered from Amazon. Will report back after install, though I'll probably wait a bit and get this done with an oil change and putting new tires on the front.