My own Pre is equipped with the Seidio Innocase and I use the ProClip designed for the Treo 700wx which fits the Pre w/ Innocase perfectly! See my review here:

http://forums.precentral.net/palm-pr...-innocase.html

My wife, however, has no interest in the Innocase so I'm looking at this option from Herbert Richter:

PALM PRE IN CAR HOLDER MOUNT FROM HERBERT RICHTER on eBay (end time 18-Mar-10 20:16:01 GMT)

Anyone have any experience with this car mount?