Hello all! Here is the scoop: I have a 1999 Cadillac Deville with 232,000 very well taken care of highway miles. Every oil change, maintenance item and part replaced has been documented since day one. I have a shudder that can occur between around 30 all the way to 65 (haven't gone any faster so could be further). It only occurs on light accelaration and going up hills. I was hoping at first that it would be something igntion related, but in the back of my mind I thought that it would be s