How do I keep the DPF clean to avoid trouble with the new MoT?

With regard to the new MoT changes for diesel cars with DPFs, how can I go about keeping my DPF clean? I have a 2017 Ford Grand C-MAX 2017, which I usually use car for city runs. It doesn't get much use...

Is my car likely to fail the new MoT?

I have two old cars registered with your website (2008 diesel Ford Focus and 2005 petrol Nissan Almera). I would like to know if they will likely fail their next MoT. Can you let me know what the changes...