The taxi is commonly found roaming the streets of Parter City. While inside, press 'Q' to start the Taxi Missions.
Taxi Driver Mission Edit
You can start a taxi mission by press Q button after you get inside the taxi. Your job is to take your passengers to the destination. There are 10 levels in this job, and after you finish the job you will got $1000. You also can get TAXIDRIVER achievement after you finish the job until level 10 for the first time.