I was in "B" last year - good view of the action
There were free shuttle busses that took you from the track to various locations in Shanghai after the race. The walk wasn't too bad but the wait was pretty long. What I did was take a regular cab from my hotel to the track and then take the shuttle bus back to SH after the race since cab drivers cannot get close to the track for pickup. The cab drop-off wasn't very close either but I don't think it was 3 miles.
Anyway, you'll be doing a bit of walking so bring good shoes, earplugs, and a raincoat.
All of us that are going this year should hook up!