Falloff is generally from 0 to 1. Change the falloff to 0. You're right that two image maps are left orphaned; they are probably alternate textures.

Verify the identity of the material by temporarily changing the red color block to green. Do you still see red bus pieces? If so, you also need to identify those material zones. It will save time if you post screen grabs of any materials left still visible.

Poser 12, in feet.  

OSes:  Win7Prox64, Win7Ultx64

Silo Pro 2.5.6 64bit, Vue Infinite 2014.7, Genetica 4.0 Studio, UV Mapper Pro, UV Layout Pro, PhotoImpact X3, GIF Animator 5