Line 13x9-inch pan with foil, with ends of foil extending over sides. Microwave butter in large microwaveable bowl on HIGH 45 sec. or until melted. Add marshmallows; toss to evenly coat. Microwave 1-1/2 min. or until marshmallows are completely melted and mixture is well blended, stirring after 45 sec.

Add cereal and chopped cookies; mix well. Press onto bottom of prepared pan. Cool completely.

Use foil handles to remove cereal mixture from pan. Discard foil. Cut cereal mixture crosswise into 8 strips. Cut 5 strips crosswise into thirds. Cut each of the 3 remaining strips crosswise into 5 rectangles.

Place 1 small rectangle on center of each of 1 of the larger rectangles; press gently to secure. Decorate with remaining ingredients as shown in photo to resemble cars, securing to treats with melted chocolate. Refrigerate 15 min. or until firm.