18-55mm is a general walkaround lens, basically landscape through to portraits or your stationary car shots, but its not really a action (sports) lens because it has a limited focal length and not very fast. As for a sports lens, depends how close to the action you can get, but something like a 70-300mm would be ideal for rallying, just understand the camera and lens limitations when it comes to camera settings and light conditions, especially for rally shots.
Basically, you'll need a camera body, walkaround lens (18-55) and sports lens (70-300mm) to start you off.