No issues with the booking process or entry to the car park. My suggestion would be a better exit process - it seems as though you have number plate recognition cameras and I cannot understand why the exiting driver has to enter the ticket, remove it, press the communication button, wait, enter the ticket again and then get the all clear. The system employed in the BAA car parks around Heathrow works better; the cameras note the number plate; the system electronically confirms it's pre-paid then the gate opens. No need for ticket entry, no need for communications, just a 2 second wait and the barrier lifts.