$9k/$72500=12.4% Rate of return (not including any closing costs which would reduce this return).  

Laundromats are open to the public, and if the local neighborhood has a high crime rate and transient population, those can be potentially expensive problems that can affect your business.

Ok, if it's still sounding do-able, the next issue is that section 179 can't be used to create a business loss, so it would only reduce your taxes for the year if your rentals are operating as a taxable gain (but rentals are often at a tax loss thanks to depreciation).  

Using a 401(k) loan reduces your emergency liquidity, which could make the investment riskier if unexpected costs arise.

I’d love to come to a meeting of the minds and a public forum probably isn’t the best place to do that.

It’s still a worthy strategy to force cash flow that’s rare to find in SoCal, especially if you can reduce the cost of construction by doing a conversion/using an ADU grant or even buying a property with an existing ADU In general, even if the ADU valuation matches your cost including grants, they are usually not worth it in southern CA in single family zones. 

I made it public to everyone. https://docs.google.com/spread...

There are two sides to every transaction: private and public..

And all of this happens during the contract period reducing purchasing risk.Great strategy especially when practiced just on the outskirts of a major metro area in a country setting(a weekend getaway property that can be marketed to city folk).  

This way we reduce our monthly legal expenses and have cash reserves to weather the next few quarters during the virus.