Depends how good you are as a sprayer and what finish you expect. As Alec said, 2litres would give a few coats over the whole car. If your priming and prep is super smooth and your technique good, and you are happy to accept a few orange peel areas, then you will be able to paint a lot of the car, possibly all.
If you want to get 10 coats on to allow wet sanding and buffing to a mirror finish, then 1L will only do 2 or three panels.
We would normally use 9L of mixed celly. you will be doing very well to get 1 good wet coat from 2L mixed, remember the first coat is a hanger coat (dusted on) then one wet after 20mins then another, this will cover the car adequately to accident repair spec, but will not meet restoration expectations for a quality job.