Hmmm Check the oil filler cap and make sure it is secure... A loose oil cap can allow additional air to circulate through the pcv system and cause a rough idle. This is only prevalent on MAF vehicles... and I have not tried this on a CF yet to see if it is sensitive to this.

Again, without having driven your vehicles, I am just guessing..

If the problem is bothersome enough, and the loose oil cap idea does not pan out, a trip in to your shop may be in order. If any TSB or service info comes out I will post for you. Next time my district rep is in the area (usually every week or two) I will ask if she has any knowledge of a rough idle condition in CFs.