I find a hotel with parking costs not much more than parking alone, and saves any worries about getting to the airport on time.
Last year I booked the Crowne Plaza through Holiday Extras, packaged with Maple Manor parking. You drive to the hotel and leave your keys at reception. Next morning you use the shuttle bus, and when you return and have retrieved your luggage you phone Maple Manor and they deliver your car to the airport.
It was a good hotel (and optional breakfast) and I only had to wait for about five minutes for my car to be returned.
