Give us a chance my man, it's a world wide thing in here, all at different time zones.
Welcome to the forum, I hope you will enjoy your Pentax kit, it's the person behind the camera that makes the real picture.
As for your car question, I would suggest your try to get a good fast prime lens, get as close as possible to the subjects and bump up the ISO as fast as you can and see how you get on.
Maybe the flash question is not linked to cars, if it is, I'm not sure that unless your real close to the car action or got a flash the size stadium floodlights, that having flash will really make that much of a difference to your shots.