The Sloppy Jalopy is Oscar the Grouch's junk car in Follow That Bird. & since his horn is broken, Oscar has a Honker in the backseat to fill that function. A ragged umbrella covers the back area, & a "Big Bird or Bust!" sign is hand painted in a ragged scrawl. The license plate reads, "SCRAM."
This car is also featured in the 1997 video Fiesta!, where it was being used as a carosa (float) by the kids to replace Rosita's broken float. Elmo thought a fairy godmother transformed his pineapple into this Sloppy Jalopy as the float for the kids.