I ended up getting my Dad a Sonus Der Wunder towel that cost £8 from eBay - it was huge as well at 24" x 30". I'm yet to try it but he loves it. Saying that the last time I washed my car I ended up using just a normal microfibre cloth and it did the job perfectly well.
Have a look at the Chemical Guys Ultra Plush Drying Towels. A very good bit of kit. I'll have these in stock at the end of Jan. Better and cheaper than the Megs water magent. These come in at £9.95 bargin!!CheersDom