I've polished out 2K scratches on clear without a rotary plenty of times, including on Audis. I've even done this, on Audis, by *hand*...not exactly fun or time-efficient, but it can be done.
Note that all 2K scratches aren't the same...the Meguiar's/Nikken Unigrit paper leaves very uniform scratches but some versions of 3M's 2K will leave random "tracers" that are a *lot* deeper/worse than 2K and might be problematic. So I'd absolutely stick with the Meguiar's/Nikken papers, or something from Mirka (also nice and uniform IME). Might want to try 3K or 2500 instead of the 2K.
Assuming the scratches are really/uniformly 2K, the PC will remove them with an aggressive pad/product combo. I'd certainly use 4" pads, nothing bigger. If the clear is hard you might want to use the 3.5" LC PFW pads, which IME take the scratches out quickly and easily.