The guys that drive in a 20-30mph limit with speed bumps with their pants on fire...why?

Sorry for the rant but around my local area there are a lot of roads with bumps. 80% of the time I turn out my road I turn onto one with half bumps that have been severely damaged by the cold weather and thus are even worse to drive over. My car is lowered on GAZ shocks and springs, rides on 17s and is polybushed front and rear completely. It isn't the nicest thing to drive over speed bumps. Usually I drive over the bump completely but in some cases I have to go over half of one and half of the other which means I have to slow right down almost to a stop and then slowly over them.

I constantly get people behind me (particularly van drivers...) sitting on my rear end in a 20mph limit with speed bumps because I'm taking it easy over the bumps. Not that they can go anywhere anyway but they still insist on sitting on my rear end, huffing and puffing, making hand gestures and some even over take me on the wrong side and round islands and then proceed to go over bumps at 30-35mph. The road in question also has 3 schools: 2 primary, 1 secondary.

Why...? Where are you going to go exactly? Why do people insist on tailgating me so closely that they may as well be in the car with me? One of these days I fear I'm going to seriously lose it with someone tailgating me over fucking speed bumps. I just don't understand it