There is a reason I asked if you were planning to manage rental properties for other owners (i.e., starting a property management business) rather than owning them yourself (or through an LLC, of which you are the sole member).
You would not qualify for Section 179 treatment nor bonus depreciation unless you were actually in business. However, it now appears as if you will simply own and hold properties for rental purposes. In that instance, your rental income will be passive and the trailer will not qualify for Section 179 treatment nor bonus depreciation; you will have to use the standard GDS schedule for depreciation.
