This is an interesting discussion. I’ve had a few loonies rage at me. How do you handle when drivers follow you way too close, like if you have to brake they might rear-end your car? I’ve had this happen a few times and it’s never because I’m driving under the limit, I usually speed moderately at 20% over. My solution has been to ease my foot off the accelerator to slowly slow down to give them a hint. Some catch on and back off, others get aggressive.
Edit: I should note that speeding up isn’t always possible because in some cases I’m behind someone else at a safe distance.
Yes. You have to adjust your speed so you have time to react for both you and the tailgater.
They have very good brakes and reaction times in Austria, because pretty much every car tailgates there, even if they don't go very fast after passing you.
Take your foot off the gas and let the car coast. It will slow down gradually and they will be forced to brake.
Turn your hazard lights on.
Flash your hazards on and off a couple of times.
Move over and let them pass if it's safe and viable to do so (you are in the passing lane and there is a slow lane to merge into etc).
Don't brake check them. It can cause you to be partially at fault in a fair number of places if there's an accident as a result,and even if your insurance doesn't consider an accident your fault, that doesn't protect you in the event that the other party decides to sue.