http://www.formula1.com/inside_f1/rules ... ions/6843/
this is the FIA regulation -the timeline till the actual getaway-
So the cars have left the pits and drive one reconnaissance lap into the grid .They are allowed to do more laps but have to use the pitlane to start their next lap .
three minutes before the start the tyres must be on the car
one minute to go the engine has to be started and all helpers have to leave the grid this acitivity has to be completed with 15seconds to go till the green light which signals the start of the formation lap.
At this point the driver must really look for reference points for his Grid slot to be able to find the ideal position to start the race.Sitting so low in the car you cannot see what is directly in front of the car .So it will not be possible to see the markers on the track!
No real race start is allowed when leaving the grid slot for the formation lap