Considering it's 300 or so years in the future, and they're so far removed from our time and technology, some of those seem right to me. And some of them are stupid. Even if they had learned about cars, are they really going to know well what an old engine sounds like, or that it can backfire and make a bang noise? Very unlikely. I'll give them a pass there.
Harry Kim is still a dipshit for not recognizing a wheel though. Unless they had BTTF2 style hovercars that still drove, which would count as an early hovercar. Let's just assume he's a dipshit though. And make/model should be pretty universal, even in a time when there's less focus on companies and profits.
And they should definitely know what an internal combustion engine is, and what "gasoline" is. It's already been in use for over 100 years in almost every vehicle ever made. I'd say that warrants a mention in any cursory history lesson.
Especially focusing on technology, and propulsion.
Morse code has been officially not a thing for a while now, although I'd expect SOS to remain part of the culture anyway, given how simple it is to implement in any situation. I could go either way on that one.
But yeah, that is a really stupid episode. The show gets so much better once it hits S3 and especially S4. So I'm not defending that episode.
I do really hate when they randomly happen upon something from the alpha quadrant (like Klingons), or even worse, Earth. What are the odds? 1 in a bazillion trillion. And I disliked Tom Paris's apparent interest in Earth's past. It was a really contrived way to shoehorn familiar crap in there.