digithor

Perhaps you can model the windshield separately from the rest of the car. Model only the nessary amount of splines to ensure the smoothest possible curve for any given shape, then subdivide (stitch) additional splines as needed for more control or just play with the bias magitude for each spline to get the curve you want. Technically, the windows and various portions of the car bodywork are not one molded piece. Work from that point of view and the curves should be easier to keep very smooth.

Given sufficient speed, I'm sure a turn like that would put the truck in the other lane very quickly. But in this animation, the truck doesn't seem to be going fast enough. Were you trying to fit the animation with the data from the accident scene and that is why it seems unusual for the truck to move that quickly? As for the animation accuracy as presented, there is a jerky movement in the sudden turn and not enough follow through considering how quickly it turned. Its almost as if a quarter into the turn the truck runs into quicksand and then the impact since you said when the animation stops thats when the impact occurrs. Maybe motion blur can help blend it better but the follow through would still be off. Just a thought but, you might try to setup a camera in an empty parking lot to mimick this shot angle and truck's movement. The swerve footage could help you smooth out the animation by actually seeing how a vehicle would behave in a sudden turn.