The instructions given prior to arriving were not particularly clear. There was no instruction as to which area of the short stay car park I was to park in. Passport security has no record of my paying for priority security so I had to find the email on my IPhone to show them proof of purchase. When I went to exit the car park after a flight from NY + flight from Heathrow the machine displayed to me i was due £100+ for parking so I had to use the intercom to sort it out. The person I spoke to I couldn't make out what he was saying due to his accent but thankfully he managed to sort it out for me. All in all I wasn't impressed in the slightest with the service!