The biggest and most luxurious SUV from Mercedes still isn't willing to show us its production metal.

The S-Class of SUVs from Mercedes is getting ready for its third generation and that requires a lot of testing in the real world to perfect the luxobarge and work out all the kinks. A prototype of the fullsize SUV was seen the other day roaming the streets of Germany and at one point it was accompanied at a red light by a lovely Ferrari 458 Spider. All the camouflage in the world can’t obscure the sheer size of this thing, which had the production headlights but not the final taillights as those were the provisional clusters used in the testing phase.

The fact that it lacked the production-ready rear lights could be a sign the GLS won’t be out very soon, so don’t be too surprised if it will debut at some point in 2019 following the launch of the smaller GLE expected to arrive by the end of this year. With each new car getting bigger and bigger, the upscale behemoth could grow furthermore to free up more space inside the already cavernous seven-seat cabin. Better packaging brought by the new underpinnings will also play a significant role in making the GLS’ interior roomier.

Should you find the regular GLS not fancy enough, you’ll have to patiently wait for Mercedes-Maybach to work its magic and transform the SUV into a luxurious living room on wheels. The jury is still out concerning whether the Maybach version will have a longer wheelbase or not seeing as how the S-Class Sedan and the opulent G650 Landaulet have both been stretched while the S650 Convertible comes with the same distance between the axles. If you’re worried the possible increase in footprint will add weight, rest assured the new platform will shave off a serious chunk of fat to offset the increased proportions.

Inline-six engines, a few V8s, mild hybrid tech, all-wheel-drive, and a nine-speed automatic transmission are all on the agenda. The interior should offer at least S-Class levels of comfort, while a GLS 63 could arrive further down the line for those with a need for speed while being cocooned in a lavish cabin.

Video: walkoART / YouTube

Gallery: 2019 Mercedes GLS screenshots from spy video

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