When Mercedes-Benz first launched the CLS-Class, it created a segment that would soon explode and a car that would soon be mimicked by its competitors. It was a big deal. Then, the second-generation CLS-Class debuted and it was gorgeous, fun to drive, luxurious and an improvement over its predecessor in every way. It was so good that BMW had to answer with the 6 Series Gran Coupe and Audi had to answer with the A7. So when news broke that Mercedes was working on a third-gen car, the automotive world became very excited. Until they saw it. At the 2018 Detroit Auto Show, the Mercedes-AMG CLS53 is the sportiest variant and it is technically quite impressive. But it’s just so hard to get past its looks.

This new CLS-Class is just not good looking and it’s a real shame for two reasons: First, the previous two generations were great looking, especially the second-gen. Second, Mercedes has some great looking cars at the moment and its design language is quite good. So this seems like a real swing and a miss for a brand that’s been belting out great looking cars.

From the front, its headlights look like they’ve been pulled from a different car and don’t seem to fit. They’re just odd looking. Not bad in their own right but strange looking on the front of the CLS-Class. The rest of the front end is fine and the hood looks cool, with its many creases. But those headlights are just off.

In profile it’s actually not bad at all, like most cars in its segment. It’s sleek, low and seductive looking, which is exactly the goal. Though, it isn’t too much of a departure from the car it replaces. I guess don’t fix what ain’t broke.

It’s out back, though, where things get weird. What was Mercedes thinking of when it designed this rear end? Those droopy, saggy taillights and weird little frown above the license plate holder make the rear look like a sad face. It’s almost depressing, especially on a car that previously looked so good.

Looks aside, though, this specific Mercedes-AMG CLS53 actually shows quite a lot of promise for the brand. Under the hood is where the big news is, as it packs AMG’ brand-spanking new straight-six engine. It’s a 3.0 liter turbocharged unit that is a technological tour de force. For starters, the engine is completely beltless, as it is in other new Mercs. So there are no ancillary components being driven by pulley and belt. Instead, everything is powered electrically by a 48-volt electrical system.

But that’s just the beginning. This Mercedes-AMG CLS53 is actually a MHEV (Mild Hybrid Electric Vehicle) thanks to something Mercedes calls EQ Boost. In reality, it’s an electric starter-alternator that acts as the starter motor for the car while also being able to add power to the wheels or even power the car on its own while “gliding” at high-speeds on the highway. It’s similar to the Belt-Alternator-Starter that Audi uses in the new A7 except that Mercedes-AMG’s is sandwiched in between the engine and transmission, as the engine lacks any sort of belts or pulleys.

This EQ Boost electric motor provides low down engine boost, adding 21 hp and 184 lb-ft of torque directly to the wheels. Combine that with an electrically-powered compressor (essentially an electric turbocharger) and the I6 is creating a ton of extra boost before the main gas-driven turbocharger even kicks in. So torque should be instantaneous, like massively punchy naturally-aspirated engine. All in, the Mercedes-AMG CLS53 makes 429 hp and 384 lb-ft of torque. Sending power to all four wheels is a nine-speed automatic gearbox with paddles. Mercedes-AMG quotes it at hitting 0-60 mph in 4.4 seconds.

Under the skin, the Mercedes-AMG CLS53 is actually quite impressive and boasts one of the more interesting engines on the market. It’s just a shame that its actual skin isn’t very good looking.