Car manufacturers give equal priority to both summer and winter trials, but the hot-weather work arguably has the greater impact. There are more people who live in areas of extreme heat than extreme cold, and some are among the richest in the world. Most of the Middle East sheikhdoms have seen the thermometer reach 50°C or more at some time in the last four years, and the wealthy inhabitants like to think that their luxury limousines and 4x4s will run reliably and remain cool to travel in, and that the expensive leather, wood and paintwork will not crack, warp or fade.