Duplo Horse Trailer Ramp / Door 1 x 4 with Handles - Mack back door

I recently bought my son a secondhand Pixar Cars Duplo set that included the character Mack. he was missing his backdoor/ramp. I managed to find some pictures online and used the back of the cargo area as a rough reference when modelling. 

I suggest printing vertically with angle at the bottom and the handles at the top. i tried printing it horizontally and it was difficult to remove the supports and the clips were very weak.