"The reason I pulled it is that I was sitting in the seat wearing a seatbelt and it is in a holster in the back of my pants. I deliberately kept it out of sight, but by the time he got to the car, I never would have gotten it out before he could get in the car. I'm going down to the gun shop to pick up a more practical holster so I never have to do that again."
I understand why you drew, and you did well to keep it concealed.
When I carry, which is seldom. I use a right side "pancake" belt holster because I am right handed. I usually wear a jacket in cold weather, or a photographer's vest in warm weather. I am slim and the pancake holster conceals my 4" barrel 15 round 9mm S&W auto OK. However, I face the same dilema when I am driving and belted. The seatbelt/harness goes right over my holster and makes a rapid draw impossible. I have considered switching to a left side pancake where I can do a cross draw. I would use an under arm shoulder holster except that I am so slender that a very noticeable bulge can be seen.
It is hard to come up with the right holster for every situation. Generally, folks that carry a Kel-Tec are using it for deep concealment, which does not allow for quick draw.
First of all, the rule should be, don't draw your gun unless you are willing to use it, not that you intend to use it. Most of the time it is not necessary to actually fire a gun to end the threat. I would not reccommed shooting someone unless absolutely necessary.
Next if someone has just tried to kill you with their car, and is either much larger or younger etc., you have the right in most places to prepare to defend yourself.
Also it makes a lot of difference in what part of the country you live. My Father caught a guy (he was a friend of my Nephew) stealing his heart medication and chased after him with a .45. Daddy shot out his tires and then called the sheriff. The deputies caught him and took him to jail. This was in rural Florida and the deputy simply told Daddy it would be a good idea next time to just call them instead of shooting out his tires. I suspect that would have been viewed dirrently in most Northeastern States.