Classic Car Insurance with No Primary Vehicle?

[markchase]

I also have access to good mass transit, and don't really need a car. Every two weeks, I'll borrow my wife's when it's my turn to shop for groceries, or I'll rent a CarShare for an hour or two. Is there any agency that will insure my classic, without forcing me to buy a clunker that will sit in the driveway - and making me pay for annual registration, inspection, and insurance? I'll pay a premium to do so - I just don't want to waste money on something I don't need.