Has anyone done this, or have any thoughts on doing it? I drove an '06 MC last night, and I love the interior lighting. I'm also curious if it's feasible to install the puddle lamps under the doors, and the lights inside the interior door pulls. Thanks...

 

All of those LEDs can be added, sure. Start with amber LEDs, 5MM and plan to sand down the LED housing when you install them - sanding the tip of the LED flat will spread the glow and soften it. It looks like the OEM ones in the 06 are flat-tipped and "frosted" just for this reason...

The OEM puddle lamp is a plastic lens with a 194 bulb in it - the only trick might be getting power into the door if it's not pre-wired. I assume you have power windows, though, so you can probably snake your wires through the existing pass-through wire cluster to ger power into there.

OR, you can go nuts and do something like THIS.