the service is generally very good, but on the last three occasions when i have booked online, when i arrive at the car park and take the ticket, it has not recognized my number plate and therefore when i exit, it asks for extra money and i have to ring the buzzer to get let out. The person is always very helpful but i shouldnt need to do this? i thought that when i approached the barrier, it would recognise my number plate, issue the right ticket and i would therefore be able to just drive out at the end. small thing but would make a massive difference to the experience. thanks