Forewarning - I did a cruise out of NOLA a few months ago, and there were SEVERAL cars at the port parking that were broken into while we were away (and not just broken into, but windows shattered, consoles stolen, etc). To me, 20 bucks a day and/or paying more than what they charge at the port is worth the peace of mind that your car will more likely be safe. Certainly cheaper than replacing several windows. Of course it wasn't the majority, but it was prevalent enough that I was very thankful we didn't leave a car there.