How to tell when a DPF regen is happening?

[ImTheRealMarco]

Hello,

I've owned my Polo 9N3 1.4 TDI for a little over a year now and it's mostly done city driving and short trips, but I've never noticed it do a DPF regen. I've never seen it idle higher than 900, besides for a bit when I first turn on the car / until it warms up a bit, and I am a bit concerned, also wondering if 900 is too much for idling, google says it should be around 800-900. The DPF is there, everything is good, I've checked it using VCDS when I bought it, it's just that I've never had it do a regen which is quite odd, especially because it's been mostly doing short trips / city driving.

I've read that the fan being on for a few more seconds after you turn off the car might indicate that a DPF was in-progress, but I've also read that this is normal / expected behaviour and that I should not be concerned about it, so, once again, here I am, asking on how to spot a DPF regen. I've never noticed anything out of the ordinary besides the fact that from time to time my throttle response seems to be sluggish.. like real sluggish, but that fixes itself.

So, does that fan running for a few more seconds after the car's been turning off mean that the DPF was regenerating, or is that normal / expected behaviour? What should I be looking for?

Thanks in advance,
Your average noobie.