This from Danny Nelms:

In addition to the pictures that have already been posted online of Ambulance 36 and  Ambulance 20.  At the manufacturer built on a Dodge chassis these pulled into the truck stop when I was getting gas tonight on my way home

A feature I noticed that I haven’t seen on previous ambulances was the red and neon green checkerboarding stripe down the bottom of the box
 
AMB 6 FDC-261
 
AMB 12 FDC-259
Chicago FD Ambulance 6

Danny Nelms photo

Chicago FD Ambulance 12

Danny Nelms photo

Chicago FD Ambulance 6

Danny Nelms photo

Chicago FD Ambulance 12

Danny Nelms photo

Chicago FD Ambulance 12

Danny Nelms photo