Interior

• 1). Add performance pedals to your Mustang. While this addition may seem minor since gas and brake pedals are relatively out of site, they can really change the look of your Mustang from the driver's seat.
  
  
• 2). Change the design of the shift knob if your Mustang has a manual transmission. The shift knob can be exchanged for something in a completely different color and shape than what comes standard. You can also change the shift knob boot to another material, like leather or suede.
  
  
• 3). Switch out the stock seats for racing seats. This is one of the most dramatic changes you can make to the interior design of your Mustang. Racing seats have a completely different look and feel than seats that come standard in any car model.
  
  
• 4). Add harness pads to the seat belt. This is a simple and cheap addition that will make the seat belt, a rather mundane looking part of the interior, stand out. Harness pads are designed to add a sporty feel to the seat belt.
  
  

Exterior

• 1). Add racing stripes or another paint design to your Mustang. Mustangs, like most cars, usually come in one solid color. Adding an additional color in the form of a stripe or another type of graphic will make your exterior stand out from other Mustangs.
  
  
• 2). Install a body kit on your car. A body kit will replace the factory front bumper, rear bumper and side skirt (or any combination of the three) for a design with a little more flare. Usually these designs hang lower to the floor and sometimes extend out more than their stock counterparts.
  
  
• 3). Replace the hood with a new one that has a hood scoop or air intake. This additional feature of the hood will draw attention to the engine area of the car.
  
  

Performance Enhancers

• 1). Install a performance exhaust tip. While this may also be considered an exterior accessory since it can be seen from outside (and look much nicer than a stock exhaust tip), a performance exhaust tip will help the flow of emissions from your car and thereby improve performance.
  
  
• 2). Add an air intake kit to your Mustang. Like the exhaust tip, an air intake kit will help the flow of exhaust from your engine and improve both torque and power.
  
  
• 3). Add performance exhaust pipes to the exhaust system. Performance exhaust pipes provide an easier path for exhaust to expel from your car when compared to factory exhaust pipes. The quicker exhaust is expelled from the car's engine, the quicker it can start burning new fuel. Again, this will improve power and torque.