i need to know from historian point of view development of internalization of carmakers in the world and than of german carmakers(focused on VW), namely when and why they invested abroad
Historically, the patterns of internationalization of the car industry have been rather complex, especially if your concept of internationalization also includes inward internationalization (e.g. licensing) and outward internationalization that is not equity based, e.g. export sales. For example, BMW's car production begun in the late 1920s when BMW (which had till then produced motorcycles and airplane engines) obtained the licence from Austin (UK car manufacturer, now defunct) to produce the BMW Dixi. In terms of export, the car industry was international almost from inception, as companies had to sell abroad to find enough (wealthy) customers.
The first foreign direct investment (FDI) is the car industry was probably done by Daimler (producer of Mercedes-Benz cars) already in 1899, when it established a subsidiary in Austria; Austro-Daimler.
For an overview and discussion of WV's internationalization, the following article can be useful: http://docsdrive.com/pdfs/medwelljournals/pjssci/2005/761-775.pdf.
A main part of internationalization is the personell strategy: You have to send the people (especially managers) aournd to really internationalize a company.