I have decided that I will do nothing to DB driver's as there are no good outcomes that can arise but rather ignore them and continue driving. If I am in the left lane I move over at the first moment possible to let them by. It is not like the DB will learn his lesson from me tapping my brakes or brighting him or driving faster/slower, etc. The only two options for him are he backs off and now I'm the DB for doing something to him or he escalates the situation (see OPs original post).

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2009 ML320 Bluetec
1985 300CD
1981 300TD

Past Mercedes
1979 300TD
1982 300TD
2000 E320 4Matic Wagon
1998 E430
1984 300SD
1980 300SD