I believe when you signal to make a right turn this means the person making a left from oncomming traffic instantly gets the right of way.
I have also noticed the tailgaiting thing getting worse the last few years. This is mostly in town, not on the freeway. I regularly drive 5 mph over the posted and constantly get someones nose up my a$$. My attitude is
"the closer you get, the slower I go" until at times I have slowly come to a full stop. I feel there are usually one or two other lanes they can use to pass. If they want to drive like Mario, let them juggle lanes!! I ain't changing lanes for a jerk and I also ain't risking a speeding ticket and higher insurance premiums for thier convenience.
I used to have a Tyotee 4x4 with rear facing KC's, that was always fun in these situations.