why do all vehicles tend to wobble when they reach high speeds and how can i prevent that?

I am not a vehicle expert but I am almost certain that it depends on the way your car moves. Even if for just more clarity, could you provide us how your car moves?

It's been there for a long time, Just balance the speed and torque or other properties?

the size of the vehicle, and the amount of force applied to it affect the movement of the vehicle..

this is solely the reason why cars have a Max "safe" speed