I've noted that the engine bay in the 124 stays clean for an absurd amount of time. I don't know how the airflow works around the engine but it looks like it's in a vacuum. My electric car's motor is always dirty and it is purposefully designed to minimize airflow into it...Whoops. By dirt, I didn't mean in or around the battery.
I meant dirt in and around the engine compartment. On a white car, you would not believe how easily the dirt literally screams in your face - "HEY! LOOK AT WHAT I'VE DONE. YOU'RE NICE CLEAN CAR AIN'T SO NICE AND CLEAN SUCKER!!!"