Only a very few cases? Oh really? If you think that you live in a pipe dream. I am not sure if Germany has been studied specifically, but other European countries have, and the USA. Minorities with ethnic sounding names in a white majority face discrimination and challenges.
http://m.nber.org//digest/sep03/w9873.html
"It indicates that a white name yields as many more callbacks as an additional eight years of experience. Race, the authors add, also affects the reward to having a better resume. Whites with higher quality resumes received 30 percent more callbacks than whites with lower quality resumes. But the positive impact of a better resume for those with Africa-American names was much smaller."
http://blogs.discovermagazine.com/notrocketscience/2010/11/2...
"Adida found that in at least two sectors, a Muslim candidate is around 2.5 times less likely to get a job interview than a Christian one, with all else being equal. These results were backed up by a large survey, which showed that among second-generation Senegalese immigrants, Muslim households earn far less than Christian equivalents."
http://writers.unconsciousbias.org/2009/09/best-man-for-the-...
"They found that resumes with Arab/Muslim names were 10% less likely to be called in for an interview and that IAT scores indicating bias against Arabs directly correlated with the likelihood of a callback.
Rooth then followed up with many of the employers who had unwittingly taken part in the first half of the study. The employers filled out three different explicit measures of bias against Arabs and Muslims and then took an IAT that paired Swedish and Arab names with work- associated words such as “lazy”, “slow”, “efficient” and “hard-working”. Not surprisingly, “the IAT scores of the 193 recruiters participating in this study show that a very clear majority associate words signaling negative productivity… with belonging to the Arab/Muslim minority”."