That SO sucks, Steve
My Dad leaves his convertible open when he parks it outside (if there's no threat of rain, of course
). After years of having the cover cut while they went for the radio, he figured he might as well save himself the price of the cover
One time they broke in and since he had finally gotten one of the radios you take with you, all they took were a pair of prescription sunglasses.
The first time they broke in, they took the radio and either didn't notice or didn't care that the keys to the car were about an inch away