The Thief Magnet

My new Van arrived on Friday and we went to Lakeside to test it out and do some shopping.

We bought some stuff and then went to IKEA to buy a bed base for the van.
When I came out of IKEA I found that the previous purchases had been stolen. It was only in the light of the next day did I realise that the drivers door look had been pulled out and I hadn’t been stupid and forgotten to lock it.

Now, of course, I am thinking that every night I sleep in the van a queue of scum will be lining up to rip open the locks and rummage through my sock drawer.
Will the sound of snoring put them off?

Maybe it's just IKEA, my old Rascal was broken into at a different IKEA and they ran off with a 9 cigarettes.

Any ideas on how to make an Expert Van more secure?