Although the GL concept came to market on an expedited timeline as a scramble to garner the large luxury SUV market then dominated by body-on-frame offerings, the initial proposal presented to the top was a unique chassis GL that was to be upmarket from the ML, and the size of the Escalade/Navigator of that vintage. Hence the plans/rumors of having it supersede the G, which had slumped in demand till late 2007 as
@MAJESTIC mention.
With the competition then being glizzed up versions of utilitarian’s counterparts, MB followed suit to save on R&D and expedite time to market.. the difference was that they’d base it on the then new mid-entry ML and extend everything from the B-pillar back to make it a 7 seater.
Though almost 20 years ago, these were bits of the candid “raison d’être” conversation I had with a MBUSA rep at it’s debut at NAIAS 2006. The “GL” ideation came from MBUSA execs, which was the first time they had significant influence on a completely new product development. As a result, the execs at NAIAS were quite pompous about their concept coming to fruition, but also not certain that it’d be a commercial success.
With the GL being a runaway success following debut, MB then introuced the GL550 a year later with a larger grill and then huge 21” wheels to capture the Escalade clientele who liked “bling”. Otherwise, the GL450 had a very tepid design.
Fast forward 20 years, MB is still reaping the benefits of the platform sharing from a R&D and margin standpoint. I doubt they will go through the effort of making the GLS a unique offering this decade.
Regarding V12s - I love a V12 as much as the next guy, but we need to be real that MB won’t invest R&D into a new large displacement engine as a singular trim level. Unfortunately those days are over… as long as MB keeps trying to shove terrible looking EVs down our throats. The current V12’s bones are 30 years old and is barely meeting emissions standards in EU markets.