I'm gonna be a broken record... My car shake rattles and vibrates. Like many, I was told it was the Alignment and Balence.. I had new tires, Balance, Rotors, Breaks and the problem still exsists... I was suprized to see so many people have had the same probles.
I'm going to work on my tire pressure. I spoke with the Cadillac dealer today and he said you have to get a "Pressure Allignment" He says there's a special machine they have to do this for $90. Bucks. I will try and see if that is the cure. Happy cadillac'n.
The car has plenty of power and is sooo comfortable. The seat warmers are great if you have back problems.
I am a mechanic, and I have worked on a few 2001 Cadillac DeVilles, and all of them that had a shake so far, it was a torque converter control solenoid in the transmission. All I can say is, try that if your tire pressure doesn't fix it. Thank you.