"I show you some cars" is awkward English. I would never say this, instead "I'll show you some cars". And this makes sense to me because future tense it often implied in Hungarian (but explicit in English)
I can think of quite a few situations where it works.
"So, how about this: You come here, I show you some cars, you choose the one you want and I buy it with my employee discount and you pay me back."
"Every week you come here, I show you some cars, and you tell me you don't like any of them."
Where is the "you" coming from in this sentence? Can it not be "I'm showing / I show some cars"?
It can mean both. "you" comes into the picture because pronouns are often just implied in Hungarian based on the type of conjugation and the author had it in mind. "Mutatok (neked) néhány autót."
It's only added to the English translation because it's very awkward in English to talk about showing something, using the direct object but not the indirect object.
So I get that the "you" is implied, but shouldn't there be an "l" in the ending then: "Mutatlok néhány autót", as a later lesson teaches?
"Mutatlak" is the correct form of that word, but it doesn't work here. It does mean "I show you", but only if "you" is the direct object. In this sentence, however, "cars" is the direct object, and "you" is an indirect object: "I show some cars to you."
This has come up in the Russian course as well - the English verb "to show" cannot stand without an indirect/dative object. In the Russian course they have the English translation of "я покажу где находится чай" rendered as "I will show where the tea is" which you simply cannot say. "I will show you/her/Pete where the tea is" etc is right. Similarly here it has to be rendered with a dative object "I show you/her/Pete some cars"
I agree that English 'show' needs an object, but I think it can be a direct (accusative) object as well as an indirect (dative) object. For example: 'He showed his cards'.
Also possible is an indirect (dative) object without a direct object: 'They think they are clever, but I showed them!'
"Showing one's cards/hand/true colours etc" is idiomatic, and doesn't follow the general rule which is that "show" has to have a dative object. In your example "'They think they are clever, but I showed them!'" there is a dative object (them) so I don't think that that invalidates my argument.
Ok, but that is really a different meaning of the word show, here equalling "exhibit" You would never say "I exhibited where the tea is" You could conceivably say "He exhibited some cars" but that would imply that they were artworks or museum pieces etc
English uses the plural here, but Hungarian does not The -t ending in Hungarian shows accusative case,
If I'm not mistaken -from a previous comment-, the word "néhány" indicates the "plurality" of the noun, so you keep it in the singular form (plus the accusative, of course).