I had pre-booked but the automatic number plate recognition didn't work on arrival so the barrier didn't open and a ticket was presented without a greeting. I only knew this because I'd used the car park before and I had been greeted by name on the machine and the barrier had opened. I had to use the help button to talk to someone who then had to look up my booking. I had to do the same on departure as a payment was demanded although I'd already paid. Not very smooth and seamless. I'm wondering if it's because I tried to enter 15 minutes early from the time shown on my booking or if that doesn't make any difference. If it does then there must be a way to deal with this scenario. I even waited the extra mins until the actual booked time before trying again but with the same result.