I also suffer from pain in the hip region from time to time and just last month it became so irritating that I brought it up to my family doctor. Now the pain that I had actually was reaching around to my lower back also.
According to the Doc, there is a band of muscles that run on an angle through the hip area and connect around back. (He showed me on the anatomical chart and I am horrible with describing this). Anyway, he said one of the worst things that we do is get into our cars one leg at a time. He said it would be best if we would sit down first and then swing our legs in, not step in with the right leg, sit down and then bring in the left leg. Apparently this motion has the tendency to aggravate the area in the hip and then gets magnified when driving. He advised doing it the "correct" way until the pain went away.
Take it for what its worth.
Of course I didn't listen. Couldn't bring myself to get into my truck like I was 80 years old with a walker.