Hello, The wife has an 08 Fabia 1.4TDi PD engine and the subframe is the same found on the MK1 fabia's (the ones with the horrible rear console bushes - or at least I find them a pain). Can the subframe from a later TDi (the common rail engines) with the changes wishbones etc fit the older chassis with a PD engine?

OK to answer my own question for anyone searching the subject in the future. Yes you can swap the subframe along with the newer style wishbones.

I'm tempted to fit vrs/audi wheel hub carriers as well so I can fit 312mm brakes (a big improvement).

In my 2013 fabia i've fitted the 312mm front and 256mm vented rear, at the front you will need the steering knuckle from a fabia with 288mm brake setup, look if all the bolt patterns are the same, don't go for audi ones because they will not fit the abs sensor (at least on the restilyng fabia)

Yeah although I've read the newer audi a1 or s1 (with a longer gap for the balljoint) will fit and can use the abs sensor.

My bad I didn’t specify the Audi tt mk1 one