The MR-S is Toyota's most recent version of their popular Mid-Ship platform that has been the favorite of many track-minded drivers for almost two decades. Although difficult to master, the MR-Platform is considered perhaps the strongest platform as the car has the ability to be a perfect 50:50 balance of weight between the wheels.
The MR-Platform is difficult to master due to the sensitivity of weight-transfer which can cause the car to seem unstable; because of this fact the alignment is absolutely CRUCIAL in this vehicle and can greatly effect the stability and handling. The rear suspension is perhaps the most important, as the traction of the rear is what is tossed around the most.
These trailing arms help to benefit the vehicle in two ways. The first and most obvious way is by eliminating the soft-rubber bushings that allow unpredictable play and movement in your suspension. This allows the driver to get a more direct feel for the car and a more predictable reaction which gives the driver more confidence.
The second way is by allowing fine-tuned adjustments to the rear suspension geometry. By changing the length of the traction rod you change the position and pitch of which the suspension rotates upon and you change the amount of "Anti-Squat" of the rear. Although the adjustment is minimal, it can change the behavior or the vehicle during weight transfer.