BERLIN, Germany - Losing 10th place in the 2012 Constructors' championship at the final hurdle was a major reason for Timo Glock's shock departure.Asked to outline when he first realised his future with the struggling Marussia F1 team for 2013 was in doubt, German Glock recalled the dying moments of the 2012 finale in Brazil."We had really counted on being able to keep 10th," said the 30-year-old, who will be replaced with an as-yet undecided "pay driver".MOVING ONMeanwhile Glock has agreed to a new deal to race for the front-running BMW team in the German Touring Car championship.Tenth place is lucrative in F1's Constructors' World championship because teams finishing lower miss out on crucial benefits as set out in the governing Concorde Agreement."That (Brazil) was when I began to concern myself with the subject," said Glock, recalling the moment when he realised his F1 future might be in doubt. “The team came to me and told me very clearly and openly about the situation. I made my thoughts about it known and eventually we sat down together and went through the certain possibilities."I then realised how difficult was the economic situation for the team and that it would be difficult to make the expected step forward. We now have a good base and I believe that the new car will be a step forward."But, still, I know what it takes to make the really big step."