Depending on who is doing the breaking in, you will never be able to stop it from happening. For some destitute souls, a pair of cheap sunglasses is an attraction to enter.In the "Don't leave anything in your vehicle world, that's a little difficult to do unless you are really, really local. Because you'll have travel "on the mainland"clothes and food stores you'd leave in the car for when you return. There might be a suitcase or storage tub that held your paddling gear and will hold wet gear when you return. So the car will be far from empty. I know you are talking about "valuables" but the expensive issue is someone breaking into your car. Any tips on how to avoid that? One person told me he leaves his glove box and maybe the center console open so someone could see, from outside, there is nothing of value in there or think the car has already been "visited".