The marks ar on the front cam towers and the washer before the sprocket. This is located at about 1pm on your left side if I remember right.
2005 320 CDI
2006.5 VW Jetta TDI
1991 560SEL (179000 Sold)
1972 280SEL 4.5 ('The Lead Sled' 320000 miles when sold.)
1972 220D (225000 when sold)