As of 9/10/10, Car Town players can level up their jobs through Job Mastery. Complete the required amount of jobs for each level and receive more XP for your completed jobs. To view your Job Mastery Level and level requirements, click on the stars above your jobs in your Service Menu. Remember that the other job will have different requirements for each level. The rewards listed above are one-time only. When you reach maximum mastery (5 stars), aside from the reward above, you will also receive a Window Tint Mastery Sign item, and it will be delivered to your Storage.