A diesel auto is, in my opinion, highly desirable. ....in theory.
However, ignoring the horrendous physics of running a fuel system at 450bar(7000odd psi

)for a minute, my concern with a front wheel drive auto especially is, limited space between the front wheels means a transvers engine of a gay wheel drive means there simply isn't room to fit an auto box on the end of the engine WITHOUT OFFSETTING THE DRIVE LINE.
As you all know the omega is rear wheel drive and the engine is mounted pointing forwards. Not side ways. This means there is acres of room to fit an auto box on the end of the engine before the rear wheels and axle get in the way.
On a front wheel drive, you have to take the drive from the crank and make the drive go round corners to fit all the gears in between the road wheel and the end of the crank. This means extra weaknesses in the drive line of the auto gear box on front wheel drives that simply don't exist on rear wheel drives.
Then, add in the low down torque of a diesel,( which is bad for autos as we know from the omega tractors killing ar25's if chipped, and sometimes even if not chipped,) then we have even more potential for the torque of a diesel destroying the auto box.
Add in possibly towing, poor servicing, and an aggressive driving style on top of that, and the odds of an auto seeing more than 60k on a front wheel drive diesel is, I would say, possibly reduced.
Some manufacturers are better than others of course, (Aisin Warner are exceptionally poor with plastic parts in the valve body) but imo, avoid a front wheel drive diesel auto, unless your prepared to do a great deal more research than asking on here in order to avoid a large bill for auto box repair.
Tread veeeeeery carefully, imo.
Heavy car, torquey engine, front wheel drive, auto box...... Bad idea, sadly. Although hopefully more modern autos have had the weaknesses engineered out by now. But how to know before buying?