Doesn't this have to do with copyright?
I notice they often censor paintings, commercial logos, or when the tv is on etc. because they don't have the rights to use it I imagine.
Maybe the law in S-Korea is different than in the USA about this, that in USA there is a level of fair-use that is allowed but not in S-Korea. I've never seen something blurred out in american TV content, and that's not because they paid for the right, it's just fair-use to use a car in a char chase no matter what the brand it is, as long as you're not doing some intentional "harm" towards the brand.