回复：

It could be one of the seals leaking in your auto-transmission. I would send the car to a transmission shop to confirm (it is usually free). However, if it is the seal problem, before I decide to fix it, I would buy a seal conditioner or leak stopper first. Then follow the instruction. If the leak is tiny, you might be able to drive it for awhile. Still this is just a temperariy solution and you do need to rebuild the transmission to get it fix completely.