Mine is the 1997 BMW M3 which was my first car irl. However, when I want to do some hill climbing looking for barn finds or it's winter and I need a something a little less slippery I'll switch to the VW Golf R which is my current car. Living in San Francisco I don't get to enjoy driving it as much as I would like also having a stick shift in a hilly city environment can be quite annoying with the constant stop and go traffic we have.
As for seasons I would have to say Autumn, I'm a sucker for those colors. However, I spent quite a while mucking around in the Winter section of the game so when I finally transitioned into Spring the contrast between grey/white colors of Winter and well all the colors of Spring was jaw dropping. I kinda forgot the game could look so vibrant! It makes Spring a very close second place.