As some of the others have said, dont be supprised by oil burners once they get going. You can easily chip them and in a straight line, once moving, they will out do a Zed. Back when I had my Leon, the diesel ones we becoming more popular for commuters as you could chip them to the same BHP as the Cupra R but they had more torque, so 0-60 the petrol won it, but if you did 20-100MPH runs the oil burner did them!
That said, the number of missed changes you had would have done you in for sure. Need to get more practice