Things are perhaps different on your side of the 49th, but why would borrowing money to "invest" in private loans be any different (from a tax perspective) than borrowing to "invest" in any other {legal} vehicle (stocks, bonds, real estate)?

get it towed as abandoned vehicle?

When I bought this vehicle I was nothing like that.

I've actually not heard mention of recreational vehicle or boats for STRs yet, so I don't know how much they've thought about it.

Even if i did have enough cash to put down for positive cash flow deals, the OC/LA deals would leave such a small cash on cash return that I may as well use a different investment vehicle. 

Maybe, but this argument is short sighted and doesn’t take into account risk.Despite what most people on here say, REI is one of the more risky investment vehicles as compared to say stocks or bonds (don’t hate me, I love REI too, I just do both).

I own a Motor Oil Recycling business.

A C-corp traditionally has been a poor vehicle for rental real estate but now with a lower 21% tax rate, is becoming a better alternative, especially compared to an LLC which can be taxed as high as a 37% individual rate since LLCs are pass-through entities. 

Is LLC the proper vehicle?

Unfortunately we both had vehicles that were also not reliable enough to make it back and forth to work so we have these loans on us now as well.