Studies have shown that crashworthiness of cars addressing fatal and serious injuries has generally improved over time. However, the development regarding injuries leading to medical impairment has not been shown to the same extent. The objective was to investigate the development of Whiplash associated Disorders (WAD) leading to long‐term consequences for adult front seat occupants and for children 0‐12 years of age in cars introduced at different year intervals and in different impact directions separated for gender. Long‐term consequences were defined as occupants with WAD symptoms at least one month and those resulting in medical impairment. The developments were studied for cars divided into intervals according to year of introduction and for frontal, side and rear‐end impacts. All adult occupants (35 611) and 76% of all children (973) reporting WAD between 1998 and 2008 were selected. Approximately 2% of the children reporting initial symptoms sustained medical impairment. The corresponding figure for adult occupants was approximately 10%. Between the introduction years 1980‐84 and 2000‐04 the proportions of adult occupants with medical impairment dropped by approximately 70% (both males and females) in frontal and rear‐end crashes, while the reduction in lateral impacts appears to be somewhat lower. For children there is a tendency that the proportion of WAD increases in newer models in frontal collisions. The result indicates that protecting children facing forward deserves more attention from the automotive industry and governmental bodies.