My first D2 was on longlife servicing from new so it had only just had its 4th service when I got it at 80K. I kept it on longlife as I did about 40K a year so that was 2 oil services a year at 18K miles each. It made it to 200K before the gearbox blew up but the engine was still perfect. Funny really, I wouldn't even consider running a V8 to that mileage now without doing the cam chain tensioners, but my 3.7 never rattled its whole life. I wish I kept it
I believe its feasible on a petrol engine which spends most of its life on the motorway. The computer decides the change interval based on driving style and the soot level which it reads from the sensor in the sump. I don't run any of mine on longlife now because they only do 5K a year and its trivial for me to change it annually.
There is no special filter for it. Just the standard one.
Rather bizarrely, Audi tried longlife servicing on diesel engines too. That gave the engines a very short life indeed since after 18K the oil was like liquid sandpaper. Most of the 2.5TDIs committed suicide well under 200K, and good riddance to them
The PD engines had a good go at it too. My 1.9TDI A6 has had 10K changes for many years and is over 250K.