I did not have a car for a long time. At first, I always put my feather coat on when I walked out. Then I felt it is not necessary cause I never feel cold. So I put my leather jacket (knee long, not thick) on instead, I did not feel cold either. I never wear my feather coat again, because I did not feel "sporty" in it.
If you are not so sure about yourself, you can bring some heavy coat here. Just don't spend too much money on it, cause you may abandon it quickly, especially after you have a car.