You beat me to this posting. I was going to tell everyone about the solution I purchased recently for security.
I purchased a 'luggage cable' in 2010 with a special padlock type attachment from an outdoor gear shop but it was a real faff to fit and not attractive. So this has new one (pair) has been perfect.
I saw these on a Morgan at the Silverstone Classic last summer and was ideal. They are a protected stainless steel cable with a good lock for securing your surf boards to your VW Camper!!
I purchased a pair of 2.5m version that is ample for a large Samsonite case (I really wanted the Rimowa Aluminium case but they are expensive!), may have to hunt other sites for these now.
I used Wetndry Boardsports on-line and I was very impressed with service and quality (they even supplied the colours I requested from the selection). No connection just very satisfied customer..
Link to the webpage 
