Instructions
Drive to a "Rim Jobs" mechanic shop. "Rim Jobs" shops are located in the Saints Row, Truck Yard, Chinatown, Barrio, Factory, Arena, Downtown and Suburbs districts. Drive your car into the garage and press the "Y" button to enter the shop.
Press the "A" button to repair your car if it is damaged. Repairs will generally cost between $100 and $500, depending on how much damage your car has sustained.
Press the "Y" button to open the car customization menu. Cycle through the customization types with the left and right triggers. You can choose between "Body Mods," "Wheels," "Colors" and "Performance" customizations.
Choose the right modifications to create the type of car you want. Neon lights, spoilers and bright color schemes will add a lot of personality to a street racer, while a sleek exterior and a convertible top will add a touch of class to a sports or luxury car. If you are creating a car to use for street racing, install a nitrous oxide boost to greatly increase your speed on long straightaways.
Press the "A" button to purchase your selected modifications. Car modifications generally range in price from $50 to $450. Press "B" to exit the shop when you are done customizing your car.