Movement of the DMF can be measured when its out, and a sensible decision made.

Depending on who is doing the job and how much the labour charges are will help you make your mind up whether to change it.

As it's juddering, and we assume thats due to clutch wear only and not other reasons such as a weak engine/gearbox mounting, sticking or worn clucth operating/release mechanism, then you should get this job done as quickly as possible, if the clutch plate wears down too far then the flywheel friction surface will be damaged, and the choice whether it needs changing or not taken for you.

If the juddering has been pronounced it won't have done the DMF any good.

My own personal thoughts - unclouded by technical facts --

Dual Mass Flywheels fail, as far as I can gather, when the springs between the two halves start to break, and the chances of the springs snapping are greater, I would assume, in a higher-powered engine or one that is driven with clumsy use of the clutch pedal. Just as both my front suspension springs broke on the coldest winter day a couple of years ago, then the springs in the DMF could fail earlier if subjected to extremes of temperature, and if you keep the car in a garage rather than on the drive, then all its bits should last longer.

And if you do replace the flywheel, then like suspension springs, the springs in the lower-priced replacements will be of a lower quality.

So my thoughts are - if you drive in a sedate and mature manner, the flywheel should last much longer than 70K miles. But then again, the clutch has failed in less than 70K miles, which could show that the previous owner is someone who drives a car hard then trades it in for a new one and lets the next owner inherit the problems which he has caused!

You just don't know, do you? Is the Mini clutch known for early failure (that is, is the clutch too small for the car?) or was the previous owner heavy-footed?

Clutch judder, in my experience, occurs when the clutch plate is down to its rivets.

If you ask the dealer to do the clutch change, try to have a dash-cam fitted first, because when you run through the video afterwards, you will most likely find that the dealer has driven the car to the local clutch and transmission specialist and got them to do the job.. but they won't tell you that! That, again, is in my experience! A Roadhawk or similar can be so useful. Surprisingly, the garage didn't notice it and left it plugged in... So you'll end up paying more than you need to 'cause the dealer will want his handling fee on top of whan the specialist charges.