Thanks for the thoughts. This behaviour similarity is exactly the reason this case has come up - ideally one would have anticipated (up-front during design) that both Sedan and Stationwagon would be siblings of a common class. However if the Product Owner calls for this never-before-imagined Stationwagon 5 years after Sedan with a two week deadline, then the most time-effective solution is to simply re-use 95% of Sedan (through inheritance) and override the couple of cases which captures the differences in behaviour between the two classes.
Ok maybe we are stretching this toy example a bit far. . .