We booked through essentialtravel.co.uk . Total charge was £137.70 for two weeks with a company called Central Car Storage. We use them every time we fly from Luton (usually at least twice per year) and we've never had any problems - they turn up for collection on time and are always waiting for us on return too. I think its definitely worth paying for this service - so much easier than waiting for the sodding bus at the car park or one parent stranded with kids and luggage whilst other parks car!