I've never seen a turbo Buick spin less than both rear tires but, I'm being told that the G80 was an option. I don't see how Buick could have sold these cars without posi. My brother in law bought his T (with G80)new in 87 and from the first day he owned it and even now with 108k on the original motor/tranny from a dead stop it won't break loose but as it builds boost it will start chattering the rears and loosing traction at the top of first and then break loose sideways when it hits 2nd. One of these cars without limited slip must absolutely blow the right rear off with any kind of throttle. Anyone know what % of these cars did or did not have limited slip rears? I didn't even think that was an option I had to look for when buying one.