Stu,
I don't know about the Costco covers, but the Cal Covers have a good warranty life, quality & weather resistance - if pricey.
PS - they also have some higher weatherproof covers if you need more protection upo there in the PNW.
You'll need to use their cover lock loops to try to discourage your local asshat(s) though, whatever you get.
Also, you may be able to have the theft covered by your auto Comprehensive coverage - depending on your policy terms & deductible (some will waive deductible for a non-fault incident/theft). It's worth looking at for a $250 cover with tax & S&H.
Tom
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