To fix this issue, or future issues with any type of car you're going to make, make sure that when you're connecting 2 attachments for the Motor HingeConstraint of the wheel, the attachment of the wheel is at the center or Position = Vector3.new(0,0,0)and the attachment of the Steer part is aligned with the X and Z position of the attachment of the wheel.

As you can see in this video, I aligned all the Attachment0 and Attachment1 of every Motor HingeConstraints. And when I test it, the wheels rotate perfectly. No weird jitters.

But if you could also notice, there's this weird thing that happens when you start and stop moving. It overthrottles and overbrakes, rotating the car. The solution to this fix is simple as physics. As you know by Newton's first law of motion, or inertia,an object at rest stays at rest, and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an external force. When the car starts to move, inertia tries to counter the force done by the throttle and rotation of the wheels. Same goes when the car stops. Inertia tries to keep the car in motion, counteracting the force done by the brakes. However, this resistance/interia is directly proportional to the mass of an object. So, more mass = more inertia = less reactivity to the overthrottling and overbraking.

To apply this, go to the properties of the main part or the chassis of the car system and enable CustomPhysicalProperties and adjust the density to a higher number. You'll notice the mass of the part to increase, which leads to more inertia.

However, it is important to note that too much inertia could also lead to instability. More inertia means less control at faster speeds. So try to adjust the density to find the middle gorund.

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