Stealing rental cars

[EightFingers]

We'll be on island in March and of course we'll have a rental car. Should we get the extra insurance to cover it for car theft? I hate to ask the "counter people" since I don't want to tip them off. Is there even such a thing as rental car theft insurance? We have great auto coverage for our personal cars here and we are *generally* covered when on trips. It would just be nice not to have to submit a claim and have our rates go up - basically keep it at the car rental level.
I've been to Hawaii so many times before and never had a problem, but after seeing what's posted here, I'm thinking my luck's gotta run out soon.