Start of AP rear brake conversion.

i know a thing or two about brakes.first a car for road use must have a non hydralic hand brake.so lock lines in brake lines are a no no.plus these devices are only designed to hold cars on the start grid until lights turn green.
you have to have a handbrake pure and simple.and it has to be cable operated independant form the foot operated system.
fitting the same size brakes to the front and rear of a car will never work,thats why no one has ever done it before.most of the braking is done througn the front wheels and the rear just helps,same as on a motor bike.too much rear brake and you skid.putting rear brakes as four pot will take up your time and effort,it wont be road legal at the end of it and more importantly the car will be dangerous.if it was really that easy and if the benifets would have made the car so much better then rover would have done it at the factory.
The abs systems helps stops a skid on the set up its designed to operate.Cars ARE BLOODY DANGEROUS and if you lose control its your life you can lose.
I know its seams tempting to fit them,after all they will look good.no outlay as you have a set what can go wrong.believe me they will not work.

I disagree with you.

I fitted 280mm discs and got far superior braking from the setup, but the problem was heat. The rears were non vented disks and warped.

The AP equiped cars are woefully underbraked at the rear for serious braking.

Fitting the 304mm discs at the rear will give stronger discs and better brakes, but a bias valve can make the rears as feroscious or weak as you want.

I would never dream of fitting APs at the rear and leave it at that as that would give an unsafe bias. I will be taking the car to a motorsport place to have the bias set up properly.