True coilover "supporting" mods

MaysEffect

It keeps the tire from changing static toe under load. Toe-out on the outside wheel being the primary problem with decreased ride height and increased spring load. It also reduces yaw which generally comes from for/aft movements. The oem rubber bushings will probably absorb up to 2degrees alignment change. Downside is you will actually induce more will spin and faster more accurate sliding in the rear with the solid arms.

NOTE - adjusting traction arm length is an even more complex adjustment that will effectively change the wheel base as well as weight jack the car if unevenly set. This change in geometry can change front wheel caster which can lead to an assortment of other steering change.

The arguments you may see about "bumpsteer" is a lose one. The bumpsteer in the rear is independent to each wheel unlike bumpsteer on the steering wheels. So the overall impact of toe change with the oem arms will not suddenly change the steering load on the car. However the solid traction arms will change the amount of load transferred across the car and act more like a solid axle and increase bumpsteer, not reducing it. In most cases this isn't a good thing but will give you much faster and accurate steering feel, something the g37 can benefit from.

The g37 actually has a better ability to handle strut tower load than the 370z as it has an upper rear deck and backseat surround to absorb deformation. But i'm not saying its a good idea in either case. For those who've actually changed to a true coilover setup can speak on wether it works better and the amount of wear.