My `01 Buick Century transmission works great when I first start up my car in the morning. But after I drive it for about 10 minutes and come to a stop light I have a hard time shifting it out of second gear when the light turns green. Any gear after that is fine. But I really have to mat it hard to get it to shift. I do not think my car can take to much more hard starts off the line like this. Everyone at the stop light thinks I'm racing them, but in reality, it's the only way from me to shift. If I don't do that and start off normally it will stay in first gear for a long time then it seems to go into neutral and I have to pull over and start over again (which is embarrassing). Again, only when I first start speeding up after a stop, and I only have problems when the transmission is warm. A cold transmission shifts perfectly....Like new. I just had the transmission flushed and it didn't resolve a thing.