"The street is paved with asphalt because that allows cars to go faster and more smoothly. It goes on hot and sticky and gets pressed out flat with a special truck that has a roller on it and dries and cures that way. The paint is so people can predict where other cars are going to be more reliably and follow those protocols themselves."

"See, okay, that's the sort of answer we were looking for!"

"So you want to know why cars as much as how cars?"

The two of them sign back and forth for a few exchanges.

"Okay, so the 'why' seems plausibly as simple as 'mortals are very slow and have no endurance', but - Emily thinks the thing we were missing is that, if this very complicated piece of machinery exists, maybe there's a chain of only-slightly-less-complicated machinery that was used to make itself, going all the way back to something we'd understand having been made by a team of crafters.  But there's still the question of - hm.  Maybe the answer is just that... there are an awful lot of humans, and they all need money to not die?"

"...there are billions of humans and they need money, yes. So if people'd buy cars, anyone who can make cars will do that and sell them."

"They sound awfully expensive.  How can so many houses afford one?"

"The houses are more expensive. But most households can afford a car, they're like, maybe take out a loan level expensive, not, cannot scrape together the money for a secondhand one on a working class salary."

"How??  I get that everyone's working, but - you're also all eating, and not off each other -"

"The share of the population that is farmers is very small nowadays, they have farm-specialized tools in the same approximate technological band as cars that make them more efficient."

"........Huh."

"Further questions?"

"It would be nice if we had a place to stay, today.  Ideally two places."

"The vamp didn't vacate a mausoleum for you?"

"...Not two of them, in any case."

"I do not intend to buy you a hotel room or invite you into my home but there are probably more where that one came from."

"Don't you feel at all bad about having to kill people, even if you think it's a necessity?"

"Why would you suppose I'd care to discuss that with you?"

"It was a rhetorical question.  There's rather an air."  He sighs.  "I'd like to go secure our lodgings."

"Sleep well. Keep your teeth amongst yourselves."