But that's not your question and you're looking to have growth and liquidity, so an insurance vehicle can help you here. 

I buy and sell vehicles, cattle, knives, etc.

Building Coverage – this mitigates and restores the building from covered losses and this coverage is required by lenders to secure loans.Building Coverage – i.e. fire, wind, water, vehicle impacts and other elements of structural damage.Loss of Rents/ Business Income Coverage– pays for loss of rental income when a building that is rented to others is damaged by a covered loss.

Other ideas make me flinch like buying materials on a cc or getting a title loan from a local bank/CU on a vehicle.

This is a situation of purchasing and selling inventory as a business, and would be taxed in the same manner as if you were purchasing t-shirts and reselling them (or vehicles, if you want to get into a higher price point object).

Drive-under garages can also be attractive to buyers who want to keep their vehicles secure and out of the elements.Additionally, it's important to have a solid understanding of the local market and demand for this type of housing.

@Shiloh Lundahl Its possible if he's going to be doing business activities (like wholesaling or being an active agent, as I said in my post) but if he's looking for an investment vehicle to double or triple in one year, I think thats a stretch and more risk than its worth. 

@Jeff KaoWould you consider SFR as more of a retirement vehicle then an income generator?

Shorty after buying my house six years ago, county vehicles would show up to inspect the property but not be able to get in.

However, how do you exit that type of vehicle.