You said the engine feature was locked for now, but I looked it up and I couldn’t find anything on this.
What if I choose to have Air conditioning, would it be to hard to render the actual compressor to be in game? Right now, the default engines have no compressors (or pumps of any kind really, but that’s whatever). I think for realism we should have the ability to choose whether or not the unit is there. As well how many belts the engine has. Right now, all the engines have multiple belts. Maybe I want one long serpentine?