Couple of months back I flew to USA from Gatwick, flight was at 11am and im a 2 hour drive away. We drove down the night before and stayed at the Gatwick Hilton over night, they do a few different deals on their website. We got the night and 14/5 days parking in the long term carpark for about £120 I think it was. This then eliminates getting up and stupid'o'clock, worrying about traffic in the morning / car breaking down etc. So we got to the hilton about 8pm, checked in, put bags in the room, they give you a voucher for the parking which you keep safe. Then drive round the corner to long term, take a ticket, park car where you like, put keys in pocket and get a bus back to the hotel. Whats nice about the Hilton is its actually joined to the hotel via a covered walkway so even if its raining you dont need a coat. When returning all you need to do is get a bus to the long term, find your car and drive to the exit where you hand in the ticket you got when you entered the car park along with your voucher and they let you out.