I still have a lot to do offline, so I'm not bothered.
Last night I managed to win the 550 Maranello Trophy, (Misano, Virginia and an awesome very fluid Canadian track, can't remeber the name of it), it was very, very hard.
The Misano race (from 16th to 1st) was a blast, after doing it I spent another 13 minutes just watching the replay. Pity we can't save those, it would make an excellent youtube video (but last night I didn't have the camcorder ready).
This Trophy (550) was perhaps the most difficult so far.
yeah some trophies are very very hard, in achievements section you can see how mucht stars are awarded for the trophy which gives you an idea about difficulty
the canadian track is called redwood park and is the same track as the gilles villeneuves grand prix circuit.