Print using at least 4 perimeters and with 20%-30% infill. I suggest some material that resists cold flow better than PLA such as PETG or ASA. Leave the part the way it is oriented to the bed so the layer lines are arranged properly for how the car will hang. Supports for the holes are optional.

Mount onto the desired surface using #6 or #8 flat head screws. Leave them slightly loose and then set the mount plumb with a level. Finally, tighten them to snug carefully (don't split the layers!) but don't clamp it down hard as there won't be any forces that require it. If you hear a crack, throw the part away.

I recommend you add a piece, or two, to the engine bodywork so that it is lightly retained into the chassis. Something like part 6013938 (¾ pin).

Hook onto the model using the lateral green piece that is near the front.

McLaren F1 mount: here