Hi
@dj_efk
The advise on the DMF might be a little vague, I've not read the specific article, however it is a fact that the DMF's lifespan will be reduced if the vehicle is labouring, or indeed if there's too much torque being applied through it.
You mention pottering about in low gears surely not doing engine harm, well there's an old addage, "right gear for the right speed".
You might also be getting confused/mixed up about DMF and engine......I don't expect the engine itself is in question in the article, just the Dual Mass Flywheel.
Think of it like trying to drive your car with the engine RPM at just below the idling speed, and how it would feel - shuddering and clearly feeling wrong - well that's what it's like to under-drive a DMF.
Maybe 2k RPM is incorrect and too high a figure for an A2 TDi 90, I don't know, but you just need to be aware that labouring any vehicle has a similar consequence as would red-lining for a similar amount of time.
As for the turbo, well.....many factors to consider there....how it's been driven ALL of it's life, weather conditions, high/low altitude, mountainous conditions, long life service done "on-time", oil quality, etc, etc.....
One of the key points is the oil.....it cools and lubricates the parts that spin at ridiculos RPM's in the turbo, so the best quality lubricant, at the correct level always, and changed regularly according to all the cars usage is vital.
Oil should really be examined for it's remaining properties, rather than on a time-line or mileage basis if you want long life from the component.
The weather conditions play a massive part in this too, as does the type of journey the vehicle does, as condensation build-up (water particles) in the oil will not only degrade the turbo, but also internal engine components.
I'd say, buy the gearbox, enjoy the car and treat it well.
If you want to potter about locally - invest in a push bike, and keep the A2 for when you want to smile when commuting.
Cheers
Jeff