I booked a DPF cleaning with Click Mechanic, it's a standard and simple on-car procedure that they offer. When the mechanic turned up, he warned me in his broken English that I would have to change the oil and filter otherwise the engine would blow up!!! Not a good start, especially when you've done a service just the week before... As I refused, then he said he can only do a off-car cleaning, but I would have to pay extra, costing even more than replacing the DPF. At this point, I realised the guy just wanted extra money and I had wasted my time booking with Click Mechanic, so I sent him back home and recommended to spend the 3h of unused labour to learn about DPF cleaning. I'll never EVER use them again, they are dishonest and I'm sure they do it with everyone and it works most of the time, but as a mechanical engineer I would never trust this company again.