How about 60 bits/s:
https://www.technologyreview.com/s/415041/new-measure-of-hum... I don't think we know enough about how the human brain works yet to give a precise value, but just on caloric arguments I would say that the mean processing power of the brain is not significantly above what we have now in general purpose computing devices.
You can find other figures, but many are in the petaflop range, well above what could be realistically installed in a vehicle.