I have a European rail pass, bought in the US, but to go really long distances I still have to order reservations (without ticket). The lines I'm particularly interested in are TGV in France, ICE, and Thalys. Everywhere I read says to do this at the station, but it seems like you wouldn't be able to make reservations for French trains from Germany, and if I wait until I'm in France it will be too late.
Deutsche Bahn's website only sells reservations for trains within Germany. Supposedly you can search and order them at raileurope.com, but every single one is "unavailable." raileurope.co.uk seems to work, but the prices for TGV lines are all about £18, much more than the €3-5 that this guy says they should be. Most other websites are a pain to navigate and only seem to sell full tickets in the end.
Surely there's another way?