If you don't expect to be giving a modern turbo diesel a weekly blast above 2,500 rpm for at least 20 minutes you could easily start running into Diesel Particulate Filter problems i.e. your DPF could start blocking up with soot.
If you don't have regular blasts on high speed roads.......your car will start forcing regeneration cycles (MPG's will plummet whilst the cycle is active).... after several failed regens....your car will go into limp mode and will require Dealership attention.
Sales people with an ounce of integrity will steer you clear of diesels if they think you'll have nothing but bother while others might mention issues but sell you the car none the less.
IMHO getting people in to a car that suits is paramount.