The car handles in Forza Horizon regressed from every Forza game except Forza 2 which could have had better controls. The music in Forza Horizon is good but the cars swerve too much and the game is not that long to beat the achievement for trying to beat the last plane in a race I cannot beat.
Must try harder springs to mind when trying to beat the plane.
Practice practice practice, You will achieve it in the end.
Do NOT just go flat out. It is more about controlled driving and not crashing and not ultimate speed at the end of the day
You have to bear in mind that the game is designed to be more of an arcade-eske game, not a simulator as FM2/3/4/5 are meant to be.