Ok fellas, last night, just driving around in the rain, and i was noticing something different, everytime i went to break, the engine made a beautiful purring growl sound that went on until i fully stopped, kept going for about 3 seconds and then went back into the ideling sound, now the sound is nice, i like it, but the fact that i havent done anything to my car in a long time, and all of a sudden its doing it, well its a bit scary... also felt it vibrating more than usual, its like it isnt changing down gear or something.. it is an auto, any ideas on what it is, and it obviously cant be a good thing