Hi,
I drive a Fit Sport AT and I too live in Brooklyn, NY. Believe it or not, I get similar mileage, like low 20's mpg. I occasionally drive from Brooklyn to downtown Manhattan on weekdays enduring endless morning rush hours traffic on BQE. I used to drive a 92 Civic and I would get very similar gas mileages. Though I am not totally happy about it, I guess it's quite common. I think a combination of being light footed, keeping up with maintenance and a clean air filter would help things a bit. My mileages in the summer is better, I would usually get around 23~24 mpg. Highway mileages for me is excellent, drove up to Toronto last year around April and the best tank I got yielded almost 38 mpg.
As with the rattling noise from the dashboard, sadly it's actually quite common for the Fit when the weather gets cold. I brought it to BayRidge Honda to have them fix this issue and now the car is much quieter.
I must say the ride is quite bumpy, especially for backseat passengers, but the fun factor of driving this car pretty much offset this for me.
