Nothing epitomizes this better then the BMW 5 series. The 5 series has been in production since the mid 70's and fills the category of mid size executive car. Currently the series is entering its sixth generation with new advancements in technology and materials. Currently it is sold in sedan and touring car models.
The series has done so well that many European nations use cars in this class as police cars and government vehicles. Make no mistake the cars not only look nice but their performance matches their appeal. Add to the fact that they are durable and very comfortable and you have a winning combination. All of these features justify the price tag that is asked for each and every model.
Of course this has been true of the early models as well. With each update in the series the cars in the lineup have received overhauls, upgrades, modifications, and redesigns to make them more appealing. Add to the mix that BMW is constantly upgrading its engine lineup to be more powerful yet more fuel efficient at the same time and you have a very reliable series.
Another statistic that's constantly under revision between series upgrades is the size of the vehicles themselves. Sometimes adding half an inch here and two inches here can make all the difference in a car. This applies to all cars not just luxury or sports models. BMW has taken this into consideration, especially since its cars are so readily available to so many.
People of different ethnic backgrounds usually have different body proportions as well. That being said the constant upgrade and redesign of the size and the interior is designed to be a one size fits all. This is for the short and skinny to the tall and rotund. Safety is another feature that's constantly upgraded and the 2011 series is no slouch in this area either.
Aerodynamics are reworked with each generation to give newer models a sleeker and more modern appearance. This of course affects more than just appearance and increases the handling of the cars themselves. It can also improve fuel economy as better aerodynamics means less resistance to the car which equals less work for the engine to do. This is something that every car manufacture tries to accomplish but BMW manages to outperform the rest as usual.