In the lease I have with my tenants, we stipulate that each unit is authorized 2 vehicles per unit.

He replied with a expletive filled text that we better not touch his vehicles. 

Checkr accesses multiple data sources, including national criminal databases with millions of records, courthouses across all 3,200 counties in the United States, state sex offender registries, the Federal Court PACER system, and state Department of Motor Vehicles.

I have mentioned this many times before but what do you think would happen to the auto industry if all vehicles had to be paid for in cash like many foreign countries.. that's why there are so few cars in many of those countries.. and what would happen to private aviation where light aircraft enjoy 90% financing for 20 years at 4 to 6% interest and there are tax benefits but they start at 400 k  and light jets that start at 3 million or light turbo props at 2 million.. yet hundreds of these are sold each year .. all because of credit.and just like commercial airliners many are leased and those leasing companies are buy 50 million dollar or 100 million dollar planes with credit not cash then leasing them to the airline.s   bottom line credit freeze's we see what happened. 

I work on my own vehicle and am always tinkering with some sort of building project.

I am most comfortable with SFR but am intrigued by a duplex to quad unit, but at the same time they worry me if I ever had to get out quickly and quality of tenant potential.So my thoughts on my options are:--Take out both HELOC's and 401k loans and sit on that cash in a money market or similar vehicle along with what I have already to wait for the crash (whenever it arrives), using my personal and rental cash flow and redirecting the extra I'm paying on those existing mortgages to pay off the HELOC and loans quickly--Use my HELOC and stockpiled cash today to go into another, cheaper market somewhere else in the US, and buy up 3-8 more properties, either leveraged or outright. 

It is good that you are able to save a lot but I think you are saving in the wrong vehicles.

You will struggle to find time to get your vehicle inspected. 

But make sure you understand that lenders will be tighter with their money, meaning higher LTV requirements, higher interest rates, etc so understand those numbers and put them in your long term calculations.maybe 1031 into other vehicles so that you don't get hit with taxes?

Your "PERSONAL" Liability Umbrella is just that "PERSONAL" It only covers you and your properties and vehicles insured by coverage underlying to the Umbrella.