What bushings are being used by Japanese tuners?

[Dogs Danglies]

Found out an interesting point on ziptied.com the other day, is that if your going for spherical baerings on the rear 4-links, its only worth doing if your upgrading to equal length links (which means alot of cutting and welding of the body) or junk the panhard rod, for a watts-linkage, as the panhard rod moves in an arc, and spherical bearings won't give like a rubber bush, so you end up flexing the body mount to provide movement, which isn't good. I'm going to stick to upgraded rubber for now, as my cars going to be about 50:50 street and track.