I'd go pre Dpf given your low daily mileage and take the exta hit on road tax . Expect low to mid 30's around town which isn't bad considering . I've had 19td cars which didn't do much more . Get one with a good history and enjoy it , there great vehicles .

Mark 2009 FL2 TD4 SE (Sadly gone)
2007 FL2 TD4 GS (The wifes , gone after 8 great years)
2012 FL2 SD4 SPORT LE(Gone and missing it)
2015 DISCOVERY SPORT 2.2SD4 HSE (For now ?)
2014 Ford Bmax 1.0 ecoboost ( Gone but what next )
2014 Ford Focus 2.0tdci Zetec S

I agree with the last post. I think the newer shape looks nicer but the majority of my journeys are <5 miles so no time for it to regenerate the DPF. I have had three FL2's and the last one was 9 years old. It drove just as well as the 3 year old one I had previously. My experience was all positive with the FL2. They also hold their value extremely well. Depreciation is something people often overlook. If you buy an old one and look after it, it will lose very little money over 2-3 years. They also sell very, very easily. I have sold three on ebay over the years within five days of listing them. Never had another car like them for ease of sale. If you can, try and buy a HSE. It will cost more initially but come resale time you will more than get the difference back. It is also a much more pleasant place to be.

Had my MY13 three years and my daily commute is two miles. Never seen a DPF regeneration warning since I've had it. Am I just lucky or do the weekend runs compensate?

I am somewhat biased as I had DPF problems on a Vauxhall Signum years ago. I swore I would never buy a car with DPF again. I think the design and technology has moved on a long way since then. A few people on here run short journeys in theirs and have had no problems. I think only time will tell. If you give it a good blast down the motorway as an insurance once a month it should keep it clean.

Look for a long lasting Si6 model and you will not have any DPF concerns.

Now with the fuel price < 1€ / liter I don't care anymore about the extra fuel I need compared to a stinky diesel car.