Howdy Chevy!
I would like to welcome you to this forum, and to responsible firearms ownership. I know you caught your share of flack, and to some extent, I can understand where that is coming from. Not agree with it necessarily, but can understand it.
In my time, I've had my house burglarized twice and held up at gunpoint while performing the routine duties of my job. I never posted about those experiences, but it became readily clear to me that I was vulnerable to unsavory elements in our society. The police response ranged from 20 minutes after having a pistol pointed at my face while being robbed to over 2 hours after one of our breakins at home.
Time passed, but the uneasy sense of vulnerablity remained. Now I own and carry a weapon for the purpose of self defense. But along with owning a firearm comes the responsibility to avoid confrontations like the one you described in your OP. I'd like to offer a couple of insights as to how your experience might have gone differently.
These guys come up behind you, tailgating with bright lights on. You already were armed... with a cell phone. Calling 911 right them to tell them you were being followed by an aggressive driver and would like to know the location of the nearest available officer could have led to a meet at a nearby location. The officer, seeing the situation as you approached, would be in a far better position to see the behavior you described and taken steps to end the encounter without the subsequent confrontation you experienced.
Or, you could simply have called 911 and told them you would be heading to the nearest police station or substation, and ask that an officer be available to intercede on your behalf. In either scenario, the situation would have been resolved without the confrontation that could have ended very badly.
Never, ever, pull over to allow yourself to be confronted directly. They had one car and you did too. There are instances when several cars might be involved and they force you to stop. But using that cell phone at the instance a situation develops could slant the outcome in your favor.
Rather than reacting in a manner to escalate the original problem (i.e. flipping them off) it is important to remain calm and think of reasonable response. Rather than pulling over, drive to another location and make a few turns to assess if you are truly being followed. That cell phone and a call to 911 should be the first move once you confirm that you are, indeed, being followed. Ask for an immediate response from the nearest officer and head yourself in his direction.
Using a firearm should be your last choice. When all other options are off the table, and you have no way out of a life threatening situation, that's where the weapon comes into play. But only as your last resort and to save your life. That call from your cell phone to 911 will be recorded and show evidence that you had reasonable cause should a firearm subsequently be required in an incident of this type.
Never, ever, brandish a firearm with intent to scare off a BG in this type of situation because it may simply cause him to draw and fire on you. Keep your cool, but be ready should you need your weapon. You produce your firearm only at the point of decision, when you are ultimately faced with 'do or die' situations. And if you must produce it to save your life or the lives of others, be prepared to fire. It is not a matter to be taken lightly or with caprice. The involvement of a firearm is a deadly situation best avoided rather than engaged. In your story, I see several instances where the confrontation could well have been avoided altogether.
The best handgun is the one you never need to draw. You need to learn how to use your firearm, practice on the range, and develop a healthy respect for what it can do. Knowing your weapon will give you an assurance that you can defend your life is the chips are down. It is a tool that you hope never to use.
I personally carry an XDm .40 cal and believe it to be a good combination of stopping power and compact size. Taking it down for cleaning and routine care is a breeze. It can easily be concealed for CCW.
But the most important weapon you possess is the thing between your ears. Think through situations as they arise and look for any/all alternatives to direct confrontation. While it is nice to be armed with a handgun, you arlready are armed with a cell phone. Grab it before reaching for a pistol where possible. Use that cellphone to avoid a confrontation rather than calling when one has already developed. Leave stupid actions to the stupid people who cause these situations. Remain on a higher level and use your thought process to work through a better outcome.
Finally, learn about situational awareness. In your story, I got the impression your situational awareness came about a bit belatedly. Once you became aware of the situation, you made the wrong moves. You paved the way to make victims of you and your girl friend. The best way to handle this sort of situation is to avoid the confrontation and let the professionals deal with the confrontations. Getting them involved as near the outset as possible can make a huge difference in whether you drive away with a smile while the cops bust guys like this, or being just another couple of bodies found along the road or DOA at the E.R.
Hope something I've said seems reasonable and logical.
Be careful out there.
Blessings,
M-Taliesin