There are times in a league that a driver gets a penalty for whatever he did during last event and he's given a drive through or a stop & go. It would be nice if the host could 'mark' a driver, so he/she has to complete the penalty during the race or get disqualified.
Another thing that came to my mind after the DTM race at KY2 was that many drivers keep crossing the yellow line entering/exiting pits. There could be a host option to "enforce" not going over the yellow line at all, or you get a penalty. Its just you can gain so much time by getting full throttle in the oval from the infield and then braking just enough not to get a speeding in pits penalty.
Just my 2+2c.
PS. Oh, classic Le mans style starting grids would be great too.