Discription of Events: I was driving down I-30 and got in to the passing lane to pass a vehicle and the black Dodge got over behind me. I was going about 70 and that was not fast enough for him so he started to tailgate me. I am in a 92 Mazda Miata, so it is struggling to go any faster. I then got over once I passed the car, and he cut them off to get behind me again. He did this for about 30 miles and then pulled up next to me and refused to let me over for my exit. I had to slow down to about 40 just to get over to my exit and he slowed down with me and followed me off the exit. Then he drove away after I made a turn onto a rural road.