Ok im getting my car ready to take my car into the dealer maybe within the week for a trade in. My leather is well taken care of so its all good. The carpets are fine they just need a good vacuum. Im going to clean up the doors, dash, etc myself. Im taking it into a shop to shampoo the interior roof cuz my dam kids and thier fingers. I could just have a shop do all this for me but im trying not to put any more money than I have to. So my main question is should I spend the money to get the engine washed? I mean is that really going to matter on what they are going to offer me for the car? Input please