Rain shy pup?

My 5 year old Australian cattle dog goes ballistic when it rains. I have had her for about 4 months now and today was the first time I've seen how she reacts to wet weather. I can understand where she is coming from as she was a hurricane rescue, when she was found she was in a drainage ditch standing in about 8 inches of water. I have tried several different things, taking her out on a leash and giving her treats so she will ociate rain as a good thing, she wont even take the treats so thats not working. I tried completely ignoring her because i know if you try to comfort a dog it only reures their fear. The only thing that seemed to work was taking her for a ride in the car which just isnt feasible everytime it starts to sprinkle. I'm at a loss, I wouldnt be quite so worried about it if she was just a little scared but she literally goes crazy. She ran into the wall twice this morning when it started and I'm just afraid that she may end up injuring herself. PLEASE HELP!!