On return when leaving the car park i inserted the ticket & barrier did not open - had to go to the customer service cabin & ticket had to be validated !!! These things happen but obviously when you have paid in advance & just want to away it does become an inconvenience !!!! Other small point - why is parking area A not in use which is the closest to the airport around the customer service cabin. Obviously not everyone can get into A but it seemed to be a massive waste of space especially at 4.00 am in the morning when you just want to park quickly & close to the terminal building.