Umbrellas are wonderful things. They keep the majority of your body dry in most types of rain. Cars are also wonderful things. They get you from place to place regardless of the weather, and give you a chance to dry off during the trip. However, these two wonderful things don't play nice together. Trying to get into a car while holding an umbrella is an exercise in frustration and dampness.
If you put the umbrella in first, you're standing unprotected in the rain (albeit briefly, but long enough to get wet) and it will drip on your seat as you reach across it. If you get in first, while protecting yourself with the umbrella, you now have to somehow fold the umbrella and get it into the car without it dripping on you. In either scenario, you still have to reach out into the rain to close the door, and depending on the angle of the rain, your unprotected side may get soaked before you do.
If you're short and/or flexible, you can try getting in through the passenger-side door, followed by your umbrella, which then doesn't have to cross the car... but if you can't easily slide from the passenger to the driver's seat, you're trying to contort yourself around while avoiding a wet umbrella.
All that is a long way to ask: How can you get from under an umbrella into a car in the rain, without getting wet?
Ideally, any answer will work in reverse, too - after all, it may not have stopped raining by the time you get to your destination. But just getting into the car dry is enough for now, because you can always keep a spare (dry) umbrella in the car to use while getting out.