Thanks to everyone for responding
1) Beard: I am using a controller to drive. It is an xbox 360 controller by rock candy, and it normally works. The only time it does not is when I am hosting a game, and I am playing with someone else. If I am hosting, but no one is is playing (either lan or online), then cars drive fine, but as soon as someone joins (either local or online), cars will not go forward or backward for me. The tires just squall, but it wont move. The wheels one even move when I steer left and right. I have also tried getting out and letting the other person who is playing with me, drive, and it drives just fine.
2) Enigmagrey: I mean both. I have played with just my daughter split screen while hosting a game, and it wont let me drive. Her, yes, but not me. And it has done with with my friend online. And it has done it when my daughter are splitscreen, and my friend is online at the same time. But again, only with me. Keep in mind, this only happens when I host. If someone else hosts, I can drive just fine. If I play the game local, with just me or split screen with my daughter, I can drive fine.
3) I was unaware there were negative weight objects in the game, to be honest. However, if they have, I am unaware of it. And I am still not sure why they would be able to drive the exact same car that I can't when I host a game.
Thank you, again.