Another issue I've noticed, which happened twice today, was changing from 3rd to 4th. I make the change, it seems to be all cool then I'm putting revs on as if the gears didn't actually engage, but I'm sure they did when I gear changed. I then need to clutch in and re-engage the gear.
Maybe it's me getting used to the gears on the C5 but the others seem to go through without issue, is there a difference for 3-4?
Probably another dealer issue. My first service is I believe 500miles, or between 300-500 IIRC, so Im only about halfway there though.