I choose to pay a little extra and park in the short stay car park. I have previously used meet and greet, which is the same distance as short stay from the terminal. On a previous visit my car was damaged by the meet and greet team, however they would not accept responsibility. With meet and greet you have no control of where your car is parked and who is parking it. For another £5 (over two/three days) you can park in short stay, pick your spot and know that no-one will be driving your car. Pre-booking online does save some money and also means that on exit you just drive off, put your ticket in the exit machine and don't have to think about payment