Jim, When I worked in my dads construction business we took the trucks home with us, any chance of your employees doing that? (I know that is a can of worms but just an idea)
People I won't rent to... LOL
I rent out my front house (currently to two helicopter pilots who always pay on time).
When the house was empty my dad had a lead "I got two collage students who's parents are lawyers... they already gave me a check."
Send the check back dad.