The big dollar Mercedes-Benz E320 Bluetec just went on sale a couple of weeks ago across the country. But diesel fans of more modest means have been anxiously awaiting the launch of the new Volkswagen Jetta CleanTDI, which had been due to hit showrooms in March of 2008. Unfortunately, it looks like issues with the emission control system to clean up the NOx is still causing VW some grief, so sales have now been pushed back to late summer. A letter from executive Vice President Adrian Hallmark to dealers explained that problems occurred during durability testing and would require more time to resolve. The company wants to make sure that the new diesels don't succumb to any of the quality and durability problems that have plagued some other VW products over the years. Hopefully whatever solutions they come up with resolve the problems quickly and robustly.