The engineers involved would be in Germany, since the design was mainly done there working with Bosch, who supplied the pollution control system components. TDI diesels with the pollution control hack were shipped to a lot of countries, including Germany itself. It might not have required that much work on the part of VW engineers since it looks like it took advantage of (presumably) test modes in Bosch' own equipment - simply turned various features on (or off) to get the desired reduction in pollution during emissions tests.
An article in the Telegraph states that Bosch sent a memo to VW in 2007 warning that use of the SW to defeat emissions test measurements would be illegal. Wonder if some VW engineer made an incautious comment in front of a Bosch representative leading to that warning.
Biting the hand that feeds IT
