Pros
You can make decent money selling used cars. New car pricing is very competitive, and most dealers pay a "mini" averaging $100-$150 on new car sales with number bonuses...10 units sold, 15 units sold, etc. You have set hours, but things are usually pretty flexible because you are not punching a clock. If you enjoy selling, and can show true concern for your customers, you can have a good career in auto sales.
Cons
Believe it or not, when I started in car sales, there was no internet. No Edmunds,Costco,Consumer Reports websites. These sites make it very easy to price shop and get reliability and ownership feedback on any make or model car. As consumers, we have all become very smart shoppers and want the best price, best interest rate etc. Downside? You will rarely make a decent commission on a new car. You must go over the car completely with the customer, and they will do a survey with the manufacturer. If they didn't like the Finance Manager for instance, it may reflect on you.