On a plane, for example, you might say "Please take my case down [from the overhead rack]".
But it could just as easily be "Please get my case down", or "get my case out". Such words can easily overlap in this context. And whilst it's probably true that we tend to associate "take" with physical relocation, a sound engineer can "take the bass down" to reduce resonance, for example.
By the same token, OP's son could have said "Get the TV out", which I suspect might have raised OP's eyebrows less. But not many people have roof-mounted TV's yet (all the ones I've seen so far are fixed into the back of the seat in front), so it's not as if we have a standard idiomatic usage for exactly this context yet.
In short, the cards are still in play as regards standard usage here, so I wouldn't like to say that OP's isn't the speech of tomorrow, today.