I don't have an LSD, but I just got a 22mm rear swaybar installed on my Viggen. For US$90 I think that is a much better investment than an expensive Quaife. Nick Taliaferro has already mentioned this on his website, it looks like that the loss of traction on the left or right front wheel is for big part due to the rear end of the Viggen not being stiff enough. The twisting in the back makes the front wheels lose contact on full throttle and the car moves left or right. This has been interpreted like torque steer or tramlining. I had my doubts about the torque steer because my car kind of oscillated between going left and right under full acceleration, even on a perfect road. With torque steer you expect the car to keep trying to move in one direction only, depending on the slight difference that the left and right drive train experience at that moment.

Unfortunately I also installed the GenuineSaab sport front and rear engine mounts and the sport transmission mount at the same time. So, it is a bit difficult to judge the effect of the fat rear swaybar alone. However, the effect of the whole setup is amazing! The car goes straight even under full torque load! Don't try this at home, but I even took my hands off the steering wheel when accelerating and the car keeps going dead straight.
Also in long sharp curves the car now behaves much better. The swaybar does what it is meant for, i.e. keeping the car more flat. I also notice that I can now accelerate much more through corners, the understeer is much less but there is still enough left to not be surprised by a sudden oversteer.

GenuineSaab has been selling stiffer sport front engine and transmission mounts for a while now. The sport rear engine mount is new. These are not race mounts, the urethane bushings still give some cushioning but they are much, much stiffer than the originals. Imho, the originals are crap for a Viggen engine. After only 60,000 miles mine were pretty much shot and I could feel and hear the engine moving around. The new mounts keep the engine much better in place and the whole setup feels much tighter. The shift stick doesn't move by itself anymore and, probably because all the slop is gone, the car now responds much more acute to the throttle.
The price that you are paying for this is a bit more vibration and noise in the cabin. The vibration is hardly noticeable. The noise is just the that sound of the engine gets transmitted more to the car chassis and into the cabin. I find it totally not disturbing, it is just that you hear the engine growling under acceleration, it doesn't drown out conversation or your stereo. So, you get for free what Ford is trying to do with the Mustang, i.e. piping engine sound into the cabin.

Highly recommended to increase driving fun.

Rating: [5 of 5 Stars!]