How do you say "so far" in Japanese?

As in "So far i haven't seen any cars go by"

- Ima no tokoro, kuruma wa ichi-dai mo tootte imasen. (So far, not even one car has passed by.)
- Ima no tokoro, kuruma ga tooru no wo mite imasen. (So far, I have not seen any car pass by.)

I suggest you download a copy of the Tanaka corpus (and remember that Ctrl+F is your friend). I have found that it often helps for such simple expressions which have a fairly direct translation.

http://www.edrdg.org/wiki/index.php/Tanaka_Corpus

for the sake of having a full answer, there is not 1 way of saying so far:

so far as "up to now" = [ima no tokoro, ima made (no tokoro), kore made]
so far as "up to here" = [kore made, koko made]
so far as limit wise, you have to use the japanese word for limit such as "gendo", "chiten", "kagiri" eg : "gentaitekina mono desu"

sorry, i read the title but did not see you specified "So far i haven't seen any cars go by"

int this case, the first comment is the correct one