I drive a 2005 chevy cobalt and am looking to add an inline transmission filter to the return line coming back from the cooler. Ive searched around and cant get a definitive answer to which line is the return line. One site says its the one coming from the top of the cooler, others say the bottom. The car uses the 4t45e transmission. Is there an easy way to tell which is which? Thank you for any help you guys have to offer.