Two tactics i usually use when i have a tailgater are:

1) Slam brakes on a couple of times to shit them up.
2) Slow right down to about 20mph in places where you know that they can't overtake you, this really pisses them off and slows their journey time down even more than if they had just been a little bit patient.

When these drivers order their new cars on the options list that they can select from it states brain for driver or indicators, on BMWs, Mercs and some Audis you can very rarely select both the brain and the indicators.