srsly, im out of ideas

The only real difference that I can notice is the tone of their voice. Male cars sound like males, and female cars sound like females. Personally, I would have given the female cars eyelashes so the difference would be a little clearer.

I thought for me is there engine or certain features like coolant, exhaust, eyes and tires

Male cars have built in car jumper cables but no car jumper receivers female cars don't have jump cables but have receivers

Some male cars have facial hair while female cars don't.

Eyeyyeyyeyeyhe