2016 Sierra Owner

Yes the cover is missing. Here is a better picture. It does look like the seat may be a little high as well.

Yup I got a 16 that's still red. I remember looking at a new 17 during an oil change. I Commented to my salesmen they switched the lights to blue. GMC has been red lights for a long time. Even their logo is red. I'm sure it was a cost saving to a bean counter somewhere and probably got an award for saving the company some money.

These are the wires like suggested above. Rear sliding window, Bose system, ETC. Its easier to build and install a wiring harness for everything and just not use the leads when not needed. That way there is no need for several different wiring harnesses for the trucks and if the wrong one gets selected or installed on the assembly line they won't have to go back and correct it.

I take mine to the local dealer. They have a quick lube separate from the service lanes. I never leave the drivers seat even during tire rotations. I used to change my own oil. It's just a lot easier, cleaner and faster when I take it in now.

14-15 were removable. The 16,17,18s were like the pictures above. This was a big complaint with the 16s redesign. It's built in to not be removable but, you can take it out like the OP did. People were also ordering the 2nd cup holders out of the 14-15 to go into their trucks. It will fit in there but there is no dedicated space or tabs to keep it there.

I get the same noise when turning to back into somewhere. I took my truck in and told them about this during an oil change. I even checked it before I pulled into the service department that morning. Well they changed the oil and rotated the tires then came and got me so I could test drive with their mechanic. It did not make the noise one single time. The advisor said it would be documented and I took off. I still hear it from time to time though.

Unfortunately it sounds like you contacted the wrong dealers. I took mine in for service about a month ago and now they call me every week about trading mine or just making me an offer. It does not seem these 2019 trucks have sold well in my area anyway. Since these trucks have hit the dealers I've only seen 4-5 on the road. My dealer still has the SLT they got back in September although it's heavily discounted right now.

When these trucks first came out in 14. The word from GM was that if the truck did not come with the option from the factory. There was no way to add it. That being said there has been some people that were successful in changing or adding a few things. As for what you want. I don't think it can be done.

I guess this is not true then?

The one we have here in town has brushes that spin front of the vehicle and back. They also have love fiber strips that move up and down against the vehicle as it travels through them.

To this day. I still have suction cup marks on my sunroof from the factory.

Damned if it's too short and damned if it's too long! Can't please everyone!

Maybe you can start your own company and build these again!!

The shutters were only started with the 17+ model years.