Just got mine today. Is there a way to tell which part # you have? Mine did not have any labels, markings, etc to identify it. The box simply says "MB". I assume if I got the 451 instead of the 451A that I ordered, it would not be good for the car/transmission (I have the auto) - if anyone knows how to tell which one it is, please let me know! Or if it really wont cause any damage if its the wrong one... Thanks! Looking forward to trying it out.