Why is my Mazda RX8 vibrating?

[gypsygrl1973]

I have a 2005 RX8 and am having trouble with it vibrating. It seems to be worse when the weather is cold. It used to vibrate only when in gear but lately it vibrates even in park or neurtal. You can't feel it while driving, only when stopped. I brought it to the dealer few months ago for a recall and mentioned this and they said nothing was wrong. But something is definetly wrong. I have driven it when it didn't vibrate at all.