If you aren't, why not? SlideShare provides an opportunity to upload PowerPoint and Keynote slideshow presentations to their website and share them with friends, colleagues and strangers. I know what you're thinking, but I could just email them the presentation! You could, but what about those "strangers" it may seem obsolete for strangers to find your presentations, but what if they're looking for them?
With SlideShare you can optimize your presentation settings for great SEO! You can upload presentations on why your dealership is better than others around you, or presentations on specific cars you've got on your lot! You could create a presentation outlining what you're looking for in a specific employee and while people search google for jobs in your area, they'd stumble upon your presentation The possibilities are truly endless!
AND while you're poking around the SlideShare website, look for a slideshow (or two) that might be able to teach you something new! Learning should never stop happening, so take advantage of all the free resources possible!