rears bolt up, you just need goodridge conversion hoses, I think big boys toys sell them? Can't remember off hand.
Fronts wont be so easy, MK3 discs have a different offset to MK2s, and I assume M4s do too, I'd assume they wont work. If you're local to bracknell I have a set of 256 hubs I'm selling for £5, and happen to have 280mm discs I'm holding for a friend, so you could pop over and dry fit the lot together to check if they're gonna work
