I can at least help you with the remote start. It turns out you have to interface with the GM security and remote keyless entry system as well as the onboard computer data bus. I did a lot of searching and found a place that handles all three pieces. Yes, three things you need. A GM passlock interface module, a data bus interface, and the remote start system itself. The one this outfit sells does everything except windows, and all from about a mile away! It also turns out that the install is not as hard as you think. Both modules are plug and play. You don't have to pull apart door pannels or anything. No meters or having your wife start the truck a gazillion times to find the right wire with a meter. I'm very good at electronics, so i'm not at all afraid of this, but I still bet it's at least a 12 pack and a shower. I haven't done this yet because I want a fast truck before I avoid frozen hair fresh out of the shower in the morning. Price? About $300, but damn nice to have.
As for the aftermarket sound, a good friend of mine that does installs told me it can't be done because the radio is somehow hooked to the anti-theft system. Notice the flashing red LED when you set your locks?
Ya, I know, I didn't want to believe it either. He said a subwoofer system under the back seat fed directly by the rear channel is a huge improvement in sound.
Good Luck
Glennz71
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