Well, Car Salesman was located in Harwood at Capital Auto Dealership where you had to impress the customer by doing certain things. In the off-road vehicle, you had to drive off-road. In the sports car, you drive fast. In the family cars, you had to drive slow. The muscle cars, you have to run over people. Sometimes, the customer wanted the car resprayed to a different color so you had to drive to the Red Light District and respray it. You do that for 6 levels and they you pass the mission.
The Bike Salesman was incredibly easier, IMO. You get more money and bonuses. You have to sell 40 bikes. Ten of each bike. The PCJ-600, Faggio, Sanchez, and Freeway. For the PCJ, you had to drive fast. The Faggio, you had to drive slow. The Sanchez, you go off-road. The Freeway, you run over and drive-by.
I over-explained, didn't I?