In general, salespeople are publicly extroverted, suspiciously confident and generally someone you're not exactly sure you should trust. Most automotive salespeople did not choose to be in their profession. Someone, my case as an example, either recommended them into it or they were lured by the thought of easy money. In theory it isn't that hard to sell a car and have a good month by selling several. In practice, it was hard improving on that number the next month and every month on.
Salespeople are under tremendous pressure to perform.
Not just pressure from the dealership, but internal pressure to constantly improve and outperform the next new guy. This is the pressure you feel as a consumer when you walk into a dealership. It's a war, and the salespeople are the infantry trying to scratch out a decent living. Generally, salespeople are there to help you make the right choice. For the career salesperson, it's in their best interest to make you happy.