One piece of advice I have never seen on any forum (yet) regarding PPCs,
COMPLAIN to the shop, supermarket, etc.
I have received a few of these notices (invoices) and I have never replied to them.
But I have complained bitterly to the shop whose car park it is.
Tell them that you are disgusted at the way they treat their customers and that you and your family will not be using their store while such measures are in place.
Also tell them that you are not going to pay and that you will go to court if necessary.
Inform them that you intend to contact "Watchdog", "You & Yours", the local paper, your MP, CAG, etc.
When you send your letter (I mean letter, not email, text or phone call!!) address it to the managing director.
Find out his/her name and send it to him/her at the head office address, not the local store.
This information can easily be found on the web.
Only give them the reference number of the notice, the name of the PPC,
the date and time of when the car was parked and the store location.
Do not say that you were or were not the driver.
Keep your letter polite (no bad language or swearing) but firm.
When I have done this I have always received a letter back from the shop telling me that the notice has been cancelled and a letter from the PCC saying the same.
Shops WANT YOUR BUSINESS, they don't want complaints.
They most certainly don't want bad publicity.
Remember the shops are the PPCs customers and they will do what the shops tell them!
I hope this works for you, it’s worth a try.
Maybe make this a sticky?