To reduce your risk of audit, you want to be sure the company you select uses the IRS' preferred method, engineering-based.

Even with "only" 4 units, that's plenty of opportunity to miss out on tax savings or, even worse, have someone do things wrong that could result in fines and penalties if you get audited.

My own CPA firm happened to be the company who audited their financials. 

It is easier for the irs to track when auditing.  

If you are audited as a real estate agent, the IRS will typically disallow the s-corp and you will owe back taxes and penalties. 

The reason for short time gap: X spun the loan off to Y and Y does an audit and throws it back: this is not A paper like you promised in the pile of deals it's in default and we don't accept it in this one 

@Austin SteedIf you can afford all the LLC's, the extra holding company is nice in case you get sued or audited. 

Some of the challenges:1) Pairing clients with properties that with an affordable plan yield the results the clients need2) Get the property into contract in this aggressive sellers' market with strong STR property buyer competition3) Deep due diligence to minimize property risk during inspection period + create best COE plan to yield the highest possible cash flow + start scheduling post-COE reno work4) After COE, get the hot potato moving- help in any way necessary to make sure my clients get this work done quickly and without complications so they can get their property on the rental market ASAP and start generating cash flow.5) Occasional STR audits as requested (always an option) by clients, to further boost their cash flow, and effectively their home value- based on income approach.

Never been audited but the system is pretty honors based anyway.

Also, many utility companies have services like energy audits (free) where they come and evaluate the unit and let you know where energy and heat loss is happening.