I'm not a personal home and auto agent, I live in the world of commercial insurance procurement and risk management.  

http://www.wsj.com/articles/texas-oklahoma-wyoming-oil-woes-start-to-hit-hard-1461749401Just read this article in the Wall Street journal, basically talking about correlation between drop in oil prices and credit card/auto/mortgage delinquencies.

Then into the following,*  Personal Umbrella, which would go over rentals, home, auto, boats, etc* Commercial Umbrella, only goes over rental propertiesPersonal Umbrellas minimum premiums for $1M can start at $150, then goes up based on # of autos, homes, boats, etc.Commercial Umbrellas typically start @ $750-$1200 per $1M depending on the state. 

After doing some research it appears that the best would be to get a Commercial Umbrella Liability Policy, which I understand could be separate from my residence/auto/basic rental house insurance, and cover unlimited number of residential properties.

But also the uncommon expenses that you may overlook, such as auto mileage, BP membership, etc.

RichWait a sec, I thought you were donating the Viper to me after buying your next car at the Auto show??

I had done this a number of times for an auto tech I rented a shop to & I charged at least 12% to carry or 50% of the re-sale profit.

When we looked at it the killer was the cost of the increased auto insurance we would need to have in order to qualify to get the umbrella not the umbrella policy itself.

You could also trade services such as carpentry, auto mechanics, painting, dental work and other services that you can do for the seller over time.4.

Perhaps an auto infographic generator or small colour coded table that people can post details of what they're looking for.