Fancy Keyless Entry

So still deciding on the purchase of a new/ish touareg but am faced with a dilemma. First world I know but I do a fair bit surfing and stash my key on the car when I am at the beach. Don't really like to put key in a towel and take it down to the sand. So wondering if there is a way around the whole keyless entry thing with the 1.5m or whatever proximity range. I know you can pull the little key out and use that but if the fob is stashed on the car anyone can open it.

Any ideas short of making a lead box wrapped in asbestos wrapped in unobtainium?