Your opinion.
 

I'm having some problems with my car which every time I go on the highway and i hit the brakes to take off and it is starting to shaking real bad. My tires r brand new and alignment. Does anyone know why it is shaking ? Thanks.

Rotors and/or balance.

do you mean hit the gas to take off?

mine does this too. I'm not sure if its because it needs an allignment, or if its something else. I searched and some people who have had the problem in the past said it went away when they replaced their struts. hmmm

Is it more of a throb feel? If the shaking is coming from when you apply the brakes, it's most likely a warped rotor problem.

Rotors usually don't warp. The feeling you are describing is from the pad wearing uneaven and creating hotspots on the rotor. The pad compound more or less melts onto the rotor creating a little ridge that the pad passes over every time the rotor completes a rotation. There's quite a detailed explaination about this and disc brakes in a site that someone posted. I'd search for it if you are curious.