240z? . ,meaning, when u start it it shakes a lot. for instance I put a water bottle on the roof of the car, then it falls off.? i dont know if im making any sense but. yeah my point is, is the car suppose to be shakey? or is it normal.?

No. Sounds like either your engine mounts are bad (unlikely), or that you have a number of cylinders that are not firing. When I first picked up my 240z, I experienced the same issue. The engine mounts looked fine, so I started pulling plugs wires off the plugs to see which cylinder was not firing. Turns out I was only running on 4 out of the 6 cylinders.

It may have something to do with the car being cold. I am not an expert, but my '73 does the same thing for the 1st 5 minutes of running after a long sleep. It does not happen when I start it while still warm, only after being parked for over 4 hours. That is the main reason that I start my car, let it idle while I smoke a cigarette, then I drive her after she has had time to warm up. I may have something else wrong with her, but it seems to work.