[Haskell-beginners] how to modify show for a list of certain types

Hi there, I have a list of say type Record which I write to a file and read back from the file if required. The list's content is a single line in the file it doesn't matter how many records the list contains. I would like to modify show for type Record in a way that show does work like the normal show but additionally adds a newline at the end of the string. I'm a bit lost how to do that. Any idea? -- Manfred