I have a question I have been thinking about for some time that I would like answered. Please have a look at the following example:

You and I talk about a subject (for example a certain car model, let's say Corvette). I show you a picture of what the car looks like and tell you that my friend Sam will buy this car model.

Later on the subject comes up again. I start talking about this Corvette and you ask me:
"What kind of car is that?"

I answer you:
"It's the one that Sam will buy."

Now, how do I say that last part in Korean (without using the word CAR (자동차)? I have trying to figure it out but I end up with the following answer:
"Sam 살 거예요."
But, then what's the difference between that answer and the answer that translates into:
"Sam will buy that [car]." ?
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In short: how do I say
"The one that Sam will buy"
and NOT
"Sam will buy that."?

Thank you!