Auto insurance is kind of a moot point here - have you guys ever seen a policy that covers the contents of the vehicle?? If the car was parked at his residence, then renter's/homeowner's insurance should cover it, but auto policies are no dice. One important thing with the homeowner's is to make sure that your policy is written to cover "replacement value"...some agents do that automatically, some don't. If your policy doesn't specifically state that, then you get dinged big time on what they'll pay you based on determination of initial cost and depreciation. With "replacement value", they'll still shoot a 20%-ish depreciation value, but you'll come much closer to getting what your property was worth/having enough to actually replace it. If you have items like a $60 Banger GT that might seem questionable to the adjuster, it's easy to show them the truth. Sometimes they just aren't familiar with a particular product market, but once they see a little, they won't haggle you much unless you're claiming something really outlandish. I had a hard time proving that a bike stolen from my hitch was worth $3200 since it was built by me from the frame up and I didn't have receipts for every item involved, but with a little explanation, an itemized list, and a few web page screen prints, I got all that I was due. Just a little harder to figure the value on things like that than, say, a couch or a television.
OP...glad you got your stuff back, that's pretty awesome! I'm really impressed that the police were so interested, too. Around here, if it doesn't involve something of grand value or has blood on it, you're hard pressed to get them to even file the report properly or get the detective to return a call.