You can make that slotted piece attached to any car you would like to use:
What you will need some UV Plastic welder material like Bondic to make the piece right on the car.
A Popsicle stick. That is the size of the slot
Cut the rounded end off of the Popsicle stick to make it square. Coat the end of the stick with oil so the UV material will not bond to the stick. Wipe off any excess oil. Clean the area on the car with rubbing alcohol. Hold the stick on the location on the bottom of the car. Build up the UV material in layers then remove the stick and sand the top edge flat.
