Most dealerships you will average somewhere between 400-500 per car that you sell, including comision, bonus, spiffs, and salary. Multiply that by how much you can sell in a month on average and there is your income. This varies but somehow will always average out to be around that number. Example is when you sell a car under invoice to move a unit you might make a flat $100, but sell a high margin pre owned also and you could make $600-$700 on that car. Its all about just selling the units and doing the best you can to hold gross, but also giving a great deal to the customer. If you sell around 10 cars a month avg. you should make somewhere between 50-60k per year (not a ton of work), if you do 13/month = 60-75k per year (requires more hustle and work ethic), 15/month= 70-85k per year and so on (plan on spending your day off at the dealership). The biggest thing that I've learned is that it is tough starting out just taking ups, so you have to be aggressive and build a client base. Expect to never get two days off in a row, and work longer than normal hours.
How much car salesmen make depends on how well they do their job. Like many retail sales people, car salesmen earn commission on their sales. An average salesman earns about $45,000 annually and a top performer can take home six-figures. Read more here: http://www.insider-car-buying-tips.com/car_salesman_salary.html