Most obviously, Günter Grass's Tin Drum, Dog Years, Cat and Mouse come to mind, and there's a great film of TD. Then there's Siegfried Lenz, The German Lesson, etc. etc. Horst Bienek's wonderful trilogy, The Last Polka, "Time without Bells" (I forget the title of the third) would also meet your purposes well, but I'm not sure that they've been translated. I wouldn't neglect the more "popular" literature, even though it tends to heroicize/idealize war, e.g. the novels of Willi Heinrich. Theodor Plievier, Stalingrad (a while since I read that!) is also useful. The problem is not in the scarcity, but in selecting from a vast corpus! But I think I'd certainly choose something by Grass. Good luck