The ideal Euro-smell is apparently difficult to define (we imagine it assaults the nostrils like a hunk of Limburger), but Kia has "developed odors for the car's interior that were pleasing to Europeans," according to David Labrosse who hails from Kia's European Research and Development Center. If an objectionable odor is found, a sample is heated up to locate the source of the sordid scent, at which time, the offending ingredient is eliminated. This is certainly a case where the nose knows.
NOTE: Despite being sourced from a UK news outlet (again, the Brits are known pranksters on this particular day of the year), we actually don't think is an April Fools joke.
[Source: What Car]