The Keeper cannot be liable and neither can the driver. They have no idea who the driver is and the Keeper is under no legal obligation to identify the driver to an unregulated private parking company.
Contacting the Starbucks is not going to work because they were closed and you were not a customer and so they really don't give poop whether you got a ticket for using their car park. I wouldn't even bother trying.
The ONLY liable party is whoever was the driver when they entered the car park. Of course, ParkingEye have no idea of the drivers identity unless the Keeper blabs it to them, inadvertently or otherwise. Only the Keeper can appeal this.
There must be a MINIMUM of 5 minutes consideration period for a contract to have been formed by conduct. Therefore it is unlikely that a contract was even formed with the
unknown driver.
I advise you to appeal this. There is no legal obligation on the
known keeper (the recipient of the Notice to Keeper (NtK)) to reveal the identity of the
unknown driver and no inference or assumptions can be made.
The NtK is not compliant with all the requirements of PoFA which means that if the
unknown driver is not identified, they cannot transfer liability for the charge from the
unknown driver to the
known keeper.
Use the following as your appeal. No need to embellish or remove anything from it:
I am the keeper of the vehicle and I dispute your 'parking charge'. I deny any liability or contractual agreement and I will be making a complaint about your predatory conduct to your client landowner.
As your Notice to Keeper (NtK) does not fully comply with ALL the requirements of PoFA 2012, you are unable to hold the keeper of the vehicle liable for the charge. Partial or even substantial compliance is not sufficient. There will be no admission as to who was driving and no inference or assumptions can be drawn. ParkingEye has relied on contract law allegations of breach against the driver only.
The registered keeper cannot be presumed or inferred to have been the driver, nor pursued under some twisted interpretation of the law of agency. Your NtK can only hold the driver liable. ParkingEye have no hope at POPLA, so you are urged to save us both a complete waste of time and cancel the PCN.
Come back when they reject the appeal. No initial appeal is ever successful but they will be required to provide a POPLA code for a secondary, supposedly independent appeal.