We used Manchester Central car park.
We arrived there completely unaware that it was un-ticketed.
We downloaded the app, followed the instructions.
We got a PCN from them a few weeks after we got back.
There was a picture of the car reg entering and leaving the car park.
Why did they not use that to time our stay, and charge the card we registered in the app, rather than sending the fine.
Unclear signage, unclear app instructions.