Did anyone get an 800 in a certain section without preparation (I.e 800 in Math)?
I got an 800 in math without preparing only because its always been my favorite subject in school so I tended to take harder math courses (AP/honors) and participate in math competitions etc. As for the other two sections, they definitely required prep. 
I got 800 in math w/ no prep, but I did a lot of math contests and such in HS.
I got an 800 in writing without prep. I had no time so I only took two practice exams, but I skipped the writing sections both times and focused on the other two sections. I really appreciate good writing so I actually find the writing portion of the SAT fun (lol).
I have quite a few friends who got 800s in Math without prep. I am more like @cityonanocean. I did poorly on my writing sophomore PSAT, but this summer I only got 2 wrong (enough to get an 800 with a 12 essay on that particular test) on my writing section of my first practice SAT without any prep, besides doing the SAT question of the day habitually for a few months beforehand.