How many ppl have managed to fit the mgf front suspension (wishbones etc) onto a metro? I understand that it gives it a little more camber

Thanks in advance

many people have done that (no me). they usually do it because the mgf subframe comes with the mount for the pg1 gearbox which is more durable when fitting an engine with more power like the vvc160 or turbo.

Would you need to fit the rear mgf subframe then to fit these wishbones?

no you dont need to do that. the mgf subframe is just an easy way to get the PG1 gearbox mount as I understand it. the lower wishbones (which is what will give you the negative camber) can be installed in your original metro subframe. in reality its just the outer ball joins that needs changing, the pressed steel part of your wishbone is the same.

Would a mgf rear subframe require much cutting to fix to a metro

having never done it I don't know the specifics of what needs cutting off, but I wouldn't thing it was a lot.