Hi:
Different engines required different reference methods for worksheets. The named literal method that you originally tried is NOT needed with the XLSX engine, but was used with other engines. Once you issue your LIBNAME statement, like this:
libname carinfo xlsx '/folders/myfolders/auto.xlsx';
You can always find out the correct sheet names to use by doing this:
proc contents data=carinfo._all_ nods;
title 'What are sheet names';
run;
title;
Use the name form that you see in the list of tables in the PROC CONTENTS output. My guess is that if you run PROC CONTENTS on your workbook, you will see AUTO listed as a table without the " 'n" named literal form.
Cynthia