Hello. I just bought a 2009 TDI Jetta with 68k miles. The previous owner had gone 3k past the 9k oil change recommended by VW. Should I add Sea Foam Motor Treatment and run it the recommended 100-300 miles before changing the oil? Also, the current oil level is as high as recommended so I am wondering if I should just add the Sea Foam or drain a little oil first? Cheers.