stupid fucking piece of shit.
1. an object, quantity, entity, or creature, that is stupid, fucking, and shitty.
2. some object that is not specifically or literally stupid, fucking, or shitty, but is otherwise objectionable or irritating.
My sfpos car didn't start today. I had to miss work.
I am neither made of, nor covered in shit, engaged in copulation at this time, nor have a below average IQ. Therefore I am not a sfpos.