Yes, custom modifications can improve a Ford vehicle's horsepower and reduce lag time between the accelerator pedal and engine response. A user on cargurus.com posted a discussion thread asking for custom ideas to improve their car beyond just audio and rims. The person is looking for custom ideas to improve their car beyond just audio and rims. They want to improve the car's horsepower and reduce lag time between the accelerator pedal and engine response. They emphasize that everything else about the car is great and like new.