Start with the part of the car that touches the ground and work inwards and up until you're happy with the result.
Keep in mind that there is little, if any, reason to increase power, as the car already makes adequate power. Those who do not believe me might be well served to consider how many bends they take with their foot off the throttle, and how soon they do lift off. The dynamics are slowing the car, not the motor.
See the link in my signature for a post with info articles.