I think just being patience and consistent with your follow ups.

So as much as I applaud any landlord that has a creative way to force tenants to consistently pay on time (towing vehicles) it seems to be more trouble than simply telling a tenant, when they pay late, that if they ever do it again they will be evicted.

Our activities for 2016 consisted of two joint ventures.  

Still, he was able to keep the place consistently rented for 3 years before selling and had no major repairs, so he thought it was successful.

I've been looking forward to "house-hacking", and I'm excited about acquiring this first investment for only 3.5-5% down payment.However, just as I was about to put in an offer on a 4-plex, I found an off-market deal consisting of 3 duplexes that I might be able to buy for less that 80% of ARV.

Is there anyone out there intentionally and consistently doing this with success? 

That's what I hear most consistently in success stories: pick a homeowner scenario (inherited house, high equity, out of state landlord, abandoned, etc.), and send many direct mailers to property owners that fit the description in your target area.

At the end it is consistency and drive that will get you to be successful! 

From there, you could take a line of credit or be refinancing to pull cash out and then really come up with a plan for that cash to multiply it through flipping, buying, rehabbing and raising rents, etc. 

The value I hope to receive in return is (1) consistent transaction flow since you will do multiple deals and (2) referrals to the other investors you know.