If you stay at the Best Western Airport Hacienda Motel, Brisbane for $159 (single or double room) you get get free open air car parking while you fly away on holidays. Airport is about 5 mins away.
So if you have an early flight from Brisbane and you need somewhere to stay overnight plus need airport parking, this would probably be the cheapest option (I guess depending on how long you were away for).
Probably won't help too many people (pretty much only regional Queenslanders flying out from Bris) but thought I'd post it anyway.