Not much use when they open the roof like a tin of beans, guess it keeps the insurance company happy
Under no illusion that if they want in they'll be in or they'll just take the whole van. It's an older berlingo and more just to put off an opportunist that may know of a quick and easy way into the the back of it by defeating the manufacturers locks.
I have a coffin type box in the back too that the only quick way into is by opening the left rear door. smashing windows won't get you into it.
If they smashed the back window glass the steel meshes wouldn't take a huge amount to defeat them either.