Can we go back to you not posting anywhere?
I've seen way too many counter-examples to find that even remotely funny.
It's mostly accurate in the US highschool/college age demo
Is it? I'd assume most young guys have sparse rooms with just a bed, a computer desk and a gaming PC or something like that. Meanwhile young women often have pretty messy rooms, clothes strewn about etc.
The key difference seems to be that women can be messy but rarely are unhygienic. You won't find germ farms growing under a girl's bed like Iron Wizard.
Like I said, I've just seen too many counter-examples, could be that I've had an anomalous experience, because I don't know a single guy who ever had a room like that, but I've known many girls who have chaotic rooms mostly involving never putting clothes away.
Cars I've seen just as many guys with disgusting cars as girls so... I dunno, meme is a massive flop to me.