Always_Ask_Questions,
“it is interesting why frumer Yidden drive similar to other MY-ers”
You already answered your question above: “You are supposed to follow local minhagim“. Based on your story, a failure to do so results in a good loud honking.
“One trick my kids and I are using is counting how much hesed you do during a trip, letting people inside the lane, make a hard turn, etc. If you remember about it, you can consistently do it at least 2-3 times per trip. “
So why not do this in a black hat and make a kiddush Hashem?
Note that the nuances of driving are complex. For example, when at a 4-way stop, it’s first come first go. If you decide to be Mr. Gracious Chosid Shoteh and let others go ahead of you, it causes frustration, as you are doing something the other drivers do not expect, which increases uncertainty (uhh why aren’t you going fella?). Safe driving requires a high level of decisiveness, so your movements are predictable. Also, if you allow kol haolam kulo to merge in front of you, that’s fine for you, but who permitted you to sentence the driver behind you to a delay?
I understand what you’re saying and I agree, I really do. I also try to let people in if I see them signalling, etc. But outside of flagrant rudeness (bad gestures or yelling, sustained honking, dangerous maneuvers that force you to take evasive action), it’s probably better for the blood pressure to work on assuming the other driver wasn’t deliberately trying to be rude than to declare him a boor. Many times when I’ve “cut someone off”, it wasn’t deliberate, and if I had a two-way radio, I’d say “oops, sorry about that.”