There isn’t anything secure left in a vehicle Skipper. I’ve yet to have water get in my cover. The fancy hard covers I’ve had leak a little bit in a car wash, but this folding soft cover that covers up over the top hasn’t leaked. It is easier to get into than a locked car. I’ll give you that. I’ve seen cops get in a lock with a slim Jim real quick as well. If cops have em crooks have em. I’ve crawled through the back window of my SUV’s more than once in the winter or at a muddy ramp. In a truck I just undo the cover before backing down.
It really comes down to what you prefer.