I think Miracles of Life was his last (non-fiction), but I've yet to read that one. It's amazing how his books seems so cinematic, your two mentions, cocaine night, super Cannes. But apart from Crash his fiction hasn't really been taken up (High Rise was p dissapiiting so not counting lol). You'd think with so much dystopian TV/film adaptations would make sense, but alas no. Probably for the best really. I suppose both cronenberg's are indebted to him massively. Have you seen the latest Brandon cronenberg? Infinity Pool?
https://www.nytimes.com/2013/02/06/books/j-g-ballards-memoir-miracles-of-life.html

