Yes, the 4th edition is out. The cover says it was revised in 1998. That's a big help. So, sometime in 1998, the 4th edition of VDA6.1 came out. Aha, I just found the month of release! Page 8 states that it came out in November of 1998! It has a couple page explanation of what changed. We had to be audited to QS9K 3rd edition and VDA6 at the same time and, frankly, there were more questions asked about QS 3rd edition compliance than about VDA6 compliance. The only real difference that I saw was the scoring that VDA6 requires. There were some other differences, but they seemed pretty minor.