Noticed that my transmission was slipping. Parked the car and came back a few days, stuck in park. The shifter moved, but R, N, and D would not engage. I noticed that the transmission fluid levels were low, so I added more fluid (4 quarts). It shifted fine, so I took it to the shop where they discovered that there was a sizeable leak between the transmission and the driveshaft. I didn't run it enough to ruin my transmission (I hope), but it's a pain to fix. Mechanic says there may have been damage to the tranny by running it dry, but since the reservoir was not completely dry, it might be okay.