In "Out of Odor", in the shot of Fifi La Fume first entering the car wash tunnel from the camera angle in side perspective, the cel background used is the same background of the aftermath of the damage to the car wash tunnel caused by Elmyra following her which happens seconds later.
In "Out of Odor", the garland adorned around the car FIfi La Fume drives disappears the moment she enters the car wash tunnel.
Elmyra who chases Fifi La Fume crashes through the car wash tunnel, causing severe damage to it; but the sign at the entrance remains intact.