I didn't quite make out what you said. I caught the last word, "Fuck," but not the rest. Now the easy assumption based on that word is that what you said was less than complimentary, but I don't know that. You could have been trying to politely inform me that I had accidentally left my back door open all day, to the discovery of which my response was also, "Fuck." I don't think that likely, I'm just pointing out that there are alternative possibilities.
In truth, based on the sounds and number of syllables I was able to make out before I was able to hear that last word, I cannot think of any coherent message that you could have been trying to deliver. There just doesn't seem to be any combination of words in the English language, and based on your accent I presume that you are a native North American English speaker, that could produce the data I've been left with.
Which brings me to my point. You obviously felt your message was important as you didn't just shout it out of the car window, you leaned out of the window to shout it. But your message never made it to me. I think this is due to a lack of understanding on your part of a very basic facet of communication. And you're not alone in this, a lot of people in cars make this mistake.
You see I was walking at speed, and you were in a car that was driving at speed, and those are two very different speeds. There's only a limited amount of time that a pedestrian is within earshot of a moving car, less when you consider that the noise of the car itself makes it more difficult to hear other noises near the car, like say the shouts of a passenger in the car.
Furthermore the noise that you are making is distorted by yet another factor. You see, since you are moving relative to the pedestrian the Doppler effect is in effect. If you're unfamiliar with what this means, I encourage you to preform a simple experiment. Get out of the car. Have the driver driver a certain distance away from you, turn around, and then drive passed you with the horn on. Notice how the quality of the sound of the horn changes? That's the Doppler effect. And just as it distorts the sound of the horn, so too does it distort your voice.
What's more, a pedestrian probably isn't expecting to be shouted at. Which means that there will be a certain amount of time between when they first hear you and when their language processing abilities are running at full steam. How much time depends largely on the person. People are not all the same, there is variance.
All of which is to say, if you wish to communicate something to a pedestrian, if you wish to insult them, to compliment them, to taunt them, to encourage them, to tell them and the world, "I am here and I demand that you recognize my existence," to come onto them, to say hi to them, to warn them of an oncoming velociraptor swarm, to build them up, to break them down, or to communicate with them in any way at all... slow the fuck down.
Perhaps the person who beeps at a pedestrian is trying to say hello, perhaps they are trying to indicate that they hate them with every fiber of their being. The pedestrian does not know. The pedestrian does not have time to know. For, unless the pedestrian has memorized the make, model, and licence plate number of every car everyone who knows them in any way might ever drive, the pedestrian has no idea who the fuck just beeped or why they did it.
Something shouted to a pedestrian will probably not be heard correctly. It might be heard in part, but probably not in full.
For myself, if you've got something important to say and I'm going up the hill (as I was) I'll be home in fifteen to twenty minutes. Call me. Just remember that I don't pick up the phone unless you start to leave a message because the number is one digit off from a radio station, also since the phone bill became my responsibility I had it stripped down to the bare basics so there's no caller ID to tell me it's you and not someone looking to request Brittany Spears because she is so totally awesome, even, like, right now.
Don't have my number? Simple solution: slow down the car, tell me why it's so damned important that you communicate with me, and either do the communicating there or ask for my number. If you've convinced me that communication really is important, I'll be receptive.
If I'm going down the hill things are more complicated. That means that I'm walking to the next city over, and there's no one number I can be reached at there. Of course, you could offer me a ride and then you'd have a few minutes where I had nothing better to do than to talk to you, and I'd have half an hour to an hour taken off my walk. Of course this requires trust and communication, which means that you still have to slow the fuck down and talk to me.
In the end, it's all about frames of reference. As a pedestrian I'm in one. As someone going full speed ahead in a car you're in another. These are two very different frames of reference and communication between them is nearly impossible. For communication to happen one of us has to move into the other's frame of reference. Either you have to slow down to my speed, or I have to speed up to yours. And since I'm not the Flash, the only way I'm going to reach your speed is if I get in your car, and for that you have to slow down first.
And that's the basic lesson. You can't say anything - bad, good, or neutral - if you maintain your speed. You have to slow down first. Trying to do otherwise will leave your attempt at communication about as successful as Dark Helmet's attempt to go from Ludicrous Speed to full stop.
Other people may get out of it just fine, but you're not going to.
And when I started composing this post in my head I had no idea it would have a Spaceballs reference in it.