Can anyone tell me which renault's had rear disk brakes?

And while we are on the subject is it possible to modify a stub axel that originally had drum brakes to take disks?
Not very well worded I know but you get the idea?

renualt 19 16v models

renault clio 16v models

clio williams

megane coupe 2.0 16v

then a lot of the fancy new ones do too

I've heard it is posisble but not worth the while to change drum's to disc's

It is possible. You can get adapters etc from burton power etc but not worth the bother really IMO.