I just purchased a used 2015 Chevrolet Silverado LTZ 2500HD diesel. It has towing mirrors but everything is manual except for adjusting the top part of mirrors. I'm guessing they are the DPN. I'm new to ownership of a Chevrolet and also would really had loved to have the mirrors with the power fold. I have also read that the premium mirrors with the power folds are usually standard with the LTZ model. I'm confused as to why my truck didn't come with the premium mirrors, would it be because it's a diesel? Also, after reading your very informative write-up, I noticed your note to get the mirrors "DQS Mirror WITH the K40 Option". Are they difficult to find? I seem to not have any luck in any searches for them. Thank you in advance!