If my buyers see pre-formed plastic on the floor they assume the entire place is junk and pass.

@Pedro Oliva Unless you'd also consider yourself a good prospect for a low cost, do-it-yourself brain surgery kit, pay an attorney to complete the U/D (unlawful detainer). 

(C) Buy those adjustable plastic grids from the big box stores and cut them to size and insert those green filter into them? 

We have to remove the cover, drape plastic underneath the unit to guide the cleaning solution and rinse water into a trash bin.

I sprayed them down with some water and gently lifted them up, trying not to break them apart, and sealed them up in plastic bags. 

The parcel with the arrow and above and below the arrow are ALL owned by this company.http://www.polydeckscreen.com/They are some kind of plastics manufacturer.  

So adding on a kitchen and bath may literally require whole new plumbing because mobiles used old style plastic cheap stuff that rots away and you can't fix or add toi. 

Replacing cabinets is something you can do yourself if you have the ability to get the cabinets into the space.If the countertops are a straight run, you can also find inexpensive plastic laminate counter tops and install those yourself.I hope I am not overselling something as being easy when it may not be.  

Also the blue plastic and the cardboard structure underneath it is an eyesore, I don't know what it's for but if it's a camouflage like for the trash and recycling bins I would build a partial fence structure with a opening that you can close to hide those, and to match the fence around the the property.  

Next I'd level any really bad spots and put down plastic sheeting.