Options not rendering on Sprout Reports report
It looks like the issue here is that the Results Template and Options Template include the file extension .twig. Removing the extension .twig should get things working:

_reports/dealer-export/options


I've added it to our list to improve this functionality in the future. We should be able to strip off the extension behind the scenes or do what we need to do with it regardless of whether you add it or not. Sprout Reports does loop through and check for all supported extension types for your site on the back end when no extension is provided.