First of all, I sincerely apologize for the comment I made in one of your scenes.
Second of all, I've seen some improvements, but there's more work to be done.
The wheel controls are confusing. Don't toggle all of them and the brake should be the down key or the "S" key, depending on what group you're comfortable with. You can override the motor speed limit by simply clicking on the motor speed number and typing a number larger that the limit, say 500, 750, 1000 or more. If you focus on accuracy though, research the speed of the car, use the top speed and try to achieve such speed by testing the car.
You should increase the sim frequency to at least 100 before making the car and when making the hinges, you should set the legacy mode for each and every hinge to 0 for better crash results. Make sure they're brakes too.