More then likely its your alignment.. But for the other guy it's a tune up.. Mines had the same problem, ended up being it needed a bad spark plug and wire change.
Yeah,
You need new wires. That happened to me a couple of months ago. I thought is was the plugs but when I got them replaced it still did it. When I got the wires changed out the car stopped jerking.
I just bought a 97 stratus and I was talking to a friend that works at a dealership and he told me that if you are going on a distant drive or if you drive around a lot, that you should put fuel cleaner to keep your engine clean.... it does help with the shaking.... if its that bad put a bottle in every time you fill with gas until it goes away... trust me it really does work