how do i discipline my twins?

I am a very strict mother. I will, when all is said and done, have raised my boys to respect people, themselves, use manners, and have confidence. I choose my discipline method according to the misbehavior. I have spanked my kids on numerous occasions. If they decide to fight over something in the car while we are driving down the road, I simply grab the item in question, roll down the window, and throw it out. They scream and cry, and I simply smirk....mission accomplished. They learned quick not to fight in the car. When we are at home and they decide to do something that they know they are not supposed to do, I make them throw the item in the garbage. While both are standing over the garbage can all teary eyed, I make them explain why the item is in the garbage, and say a brief goodbye to said item. They haven't thrown a ball in the house since!!!! When they say bad words or talk back to an adult, they get a pump of soap in the mouth. If they do something dangerous that puts them in harms way, like going in the road after a ball, they get spanked and put in time out. I have found that the more drastic the punishment is the first time, especially with boys, the more effective it is. My boys will push the line all they can, but they also know, mommy means business and mommy is consistent.