I think this is clearly not on topic. The test is primarily, would an expert in personal finance be an expert on this question? And in that it clearly fails: expertise in personal finance likely makes you worse at answering this question if anything, as it makes you more likely to buy an intelligent car rather than a luxury car.
The expertise to answer a question about "what a luxury car has over regular cars" is that of a car expert, not a finance expert, and so it is off topic here.
It's not that it's opinion - on a car site, that question would be totally fine, in my opinion. It is the topicality itself, not the opinion, that makes it inappropriate for this site.
Now, I think a question like, "Can you save money buying a well-built, more expensive, new car, rather than a cheaper brand or used car", that's fine because it addresses the personal finance aspect. But "what is the advantage of a luxury car" does not.
Edit: I want to specifically address what the OP of that question meant, given their comments in this thread.
My question meant, how to justify the higher price of luxury cars in comparison to their counterpart and when test driving these vehicle what specifically to look for.
Taking that in pieces:
how to justify the higher price of luxury cars
This is the part that is clearly opinion, and doesn't really fit on the site, though I think we've had questions in this vein before. By itself it might be an okay question, but the answer is really simple - because people like nice things, and sometimes the point of having money is to have those nice things. The detail beyond that - what's in luxury cars in particular that makes them nice and worth buying - isn't on topic here.
in comparison to their counterpart
This is where we head into automotive and not into finance.
when test driving these vehicle what specifically to look for.
And this is definitely automotive. This is great on an automotive site (the OP of this meta question suggested one, I believe, though I can't speak for that site's topic area). It's just not a finance question - it's something where you need to know things about cars to answer.