UBTI exposure is not impacted in any way by a Solo 401(k), thus my clarification.There are 3 layers of alphabet soup here:Tax on UBTI  (unrelated business taxable income) is generated when a tax exempt entity engages in a trade or business on a regular or repeated basis. 

The access to the car wash, what type model it is, the traffic counts, how many other car washes in the area, sightlines to the property ( on a hill,down in a hole,level), any cross anchor larger feeder traffic to site, parcel size layout and shape, etc. all play a vital role in the long time success of the dirt value along with other demographic metrics of course.There are not newly minted national credit leases at 9 caps with retail.

I also know that a team effort is vital in this as the property manager I have found has a good idea into estimating ARV, knows contractors and does BRRRR himself.

.,) (4) separate your assets from your operations [operations contain the most liability,] (5) introduce layers of anonymity to hide your assets from prying eyes.I approach these issues from the mindset of being an investor myself, so it all has to come together in a way that is profitable.

You may need a mason now to put up a layer of cement over the dirt first.

There is a steep enough learning curve to the first property without layering the complexities of a multi on top of everything else.

The seller is asking for $115,000 but I was going to offer $110,000I haven't seen the inside of the house, but since the house is fully occupied I wasn't going to do any repairs on the place yet.Down Payment: $23,000My analysis says:  $1,500.00 MONTHLY INCOME $847.15 MONTHLY EXPENSES $652.85 MONTHLY CASHFLOW 11.51% PRO FORMA CAP $13,233.00 NOI 30.13% CASH ON CASH ROI 11.51% PURCHASE CAP RATEDo these numbers make sense or am I missing something vital.

Even if it was legal you run several risks.  1) You would permanently damage your reputation in an industry where reputation is vital to get deals.   2) You risk major tax implications related to large capital gains.  3) Comps are not solely based on on the units you want them to be based on.  4) Even if this hypothetical plan worked exactly as you laid out you would be extremely over leveraged and underwater on the other units as you pulled out falsely inflated equity. 

Regardless, moisture will make a mess of your hardwoods, so I'd suggest a vapor barrier in the crawl and another between your hardwoods and new flooring if you put down another layer.

The walls have layers of paint, carpet was dirty, and since the house is a little older the floor has settled and warped a bit.