Always thought that if the first 9 alpha characters are the same, then it should work as the last character represents a revision number. Though I found this tidbit elsewhere:

Fits 2006-2008 Audi A4 2.0T - Fits from last six of Vin #165001-999999, split is in model year 2006

Pressure regulating valve that bolts to front of head, also called the PCV valve.

If you are experience a loss of boost and also oil around the oil cap then theres a good chance your factory PCV valve is shot. Replace it with this updated VW/Audi part to get things running how they should be.

NOTE: When replacing with this version it is required that the breather hose must also be changed with part number 06F103215A

FITS: 2006-2008 Audi A4 2.0T - Fits from last six of Vin #165001-999999, split is in model year 2006

The last six digits of mine falls out of that VIN range. I believe I've been running the N version for nearly the last three years and did have it checked out when it was taken off to get at the injector and it's fine so I'm not going to even bother with this unless it fails.