My Navigator ...is a huge SUV with a "package" area exposed to the passenger compartment. There is a lot of glass too and not much I can do with that.
...there are some other measures I can take to reduce the exterior sound.
Absolutely! The CLD is for panel vibration and while that does attribute to some level of noise, your best bet for general noise reduction would be MLV combined with a product like the 3M Thinsulate or Resonix Fibermat. I'll explain, further -
You would want the MLV to cover as much surface area as possible (100% if possible) - behind each door panel, the floor (especially at each wheel well), and all the side panels between the doors and hatch. Fill those same areas with thinsulate (but don't compress - that's why different thicknesses are made) And, certainly, more than you'd ever think possible, drop the headliner and give the roof the same treatment. The roof might be the *ONLY* place I would suggest some use of a CLD, because the panel is just SOOOO large, it can't help but cause resonance while running the roads.
An effective CLD product only needs about 30-40% coverage to achieve it's most efficient results. You can't go overboard but anything more than that will give diminished results. But don't even bother with taking the trim and panels off if you're not ready to completely FILL 100% of the area with a sheet of MLV (or lead) and a product like thinsulate!
The analogy that's most often used with MLV and thinsulate is when you crack a house window and your neighbor is running a loud lawn mower... Just that small couple inches brings nearly as much noise as if you opened the window, entirely. If you're not prepared (

and

) to close that window completely then it's just not worth getting started, as your results won't be effective enough to hear a difference!
I'll try getting some more pics to you, tomorrow, if work progresses. (weather and health dependent, at this time)