Why is my car shaking still?

I have a 99 ford contour, 4 cyl 2.0 liter engine. In the last few months I have replaced both lower control arms in the front, the ball joint bearing, tie rod end and cv axle on driver side. I replaced my brakes, bought new (used) tires and got my alignment done twice. My car still shakes on the freeway. It has been very hard to get around because I'm too nervous to drive my car like that. I have spent over a grand trying to fix this car. I'm taking it as a loss, but I'm still curious to find out why it would still shake.

I have taken it many places including Sears automotive. I have gotten most of the work done by a professional. They said the lower control arm would fix it. That was like three months ago.

Why have you not had a garage check it over. Professional and experienced mechanics have means to check.yet and fix such things. Possibly outweighing our desire to save labour fists by getting it right first time.
Even a weak damper. Bush etc can effect car and handling.

If it is shaking of the steering wheel there could be a couple of problems.
One, the tred on the tires are wearing down wrong. Happens a lot on that is why I buy my tires new.
Two, the wheel rotors on your vehicle could be off but I wouldn't know why they wouldn't have checked it when you were getting your vehicle serviced.
And three, when I had a compact i had these clip on disk front brakes and the clip broke after I started driving and it became a free "floating" brake. And would cause a serious wobble from the front end.

I say take it to a vulcanizing tire shop. They are true masters of the problems like yours.

Maybe it was in an accident prior to you getting it and has a bent frame that would do it