Hey dude,

How's your weekend?

Suspension tuning is always something that the individual has to go out and have a feel for it.
Every driver is different and I can give you a clear example --- Rob from Maximum drove just a avg Group N rally car and won the Aust Rally some years back --- so basically, the actual vehicle coupled with the individual's driving style, will determine what whether he wants to stiffen the car suspension up whether it is front or rear, and how he likes to take his corners.

So basically, if you were installing the coilovers, my suggestion is for you to get a feel for the car first and then come back and decide which aspects of the rex's suspension you want to improve on.

Regards,
Mao