I saw this movie in the 80's late night. I was mesmerized by the story line. Why?? I was in a band in the 60's and early 70's and the personality conflicts and drug experienced were so much like we experienced. I only saw it once and expected to see it on TV again. But never did. I was confused and thought that the movie was called "Thunder Road". And just today (2007), I tried "Thunder Alley" and I found it.
I really can't comment details about it, because it was so long ago. But what I remembered in the ONE time I saw it was that it seemed so accurate to what I experienced.
Wow, it would be so great to find this movie on DVD. I'd want to add it to my private collection.
All I can say is... If you were ever in a band and you can find it to watch it, do so. You'll love the movie.