fbk – did you ever resolve this problem?
I am picking up a new E-120 in a couple of weeks and I am having a similar dilema.
The shop I am buying it from have suggested that I DO NOT use any type of carrier that clamps to the carbon frame. That would rule out most conventional roof top carriers, regardless of whether or not they were capable of gripping the frame in the right place. I am not particularly keen on a form mount carrier. Surely it must put considerable force through the forks when the car bounces along?
An alternative might be to use my existing Avenir boot rack with a false cross bar convertor (http://www.edinburghbicycle.com/ebwPNLqrymode.a4p?f%5FProductID=1975&f%5FFullProductVersion=1&f%5FSupersetQRY=C163&f%5FSortOrderID=1&f%5Fbct=c003154c003131c003181) – this attaches to the headtube and the seat post, so metal and metal. Hopefully when the bike is tied in the only part of the bike that would be in contact with the rack would be the non drive side crank arm.
Has anyone had any experience of using these devices, particularly in respect of a carbon frame?