Yes, it's true that the current JGC platform was derived from the Merc ML platform.
Relative to your question, the Summit comes with the cover over the hitch receiver and towing electrical as standard. AFAIK, it's not available on other trim platforms that have the factory tow installed...the Summit has a completely different rear (and front) fascia, so a retrofit would be not so much fun and pricy. You could have a body shop spray that area with body color to help it "disappear" a little more, but honestly, it's not so bad looking as it is, especially since it's well integrated and doesn't hang down. You can also cover it with a step inserted into the receiver or bling it up with a memento of your favorite sports team or something...
2012 Grand Cherokee Overland Summit - Winter Chill with New Saddle interior. 5.7L HEMI V8 - Nitto NT421Q "shoes"
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