What is it?
Think of it as a baby CLS and you won't go far wrong. Merc has created an entirely new niche with the CLA - no-one else makes a four-door, coupe-esque saloon of this size.
Don't I recognise it from somewhere else?
Probably. A near identical concept, called the Concept Style Coupe (CSC), was shown in 2012 and that whetted people's appetites for this production version.
But there's a snag. Not only was the Concept wider, it also sat on massive wheels - compared to it, the CLA doesn't look anywhere near as purposeful.
Side-on, the CLA appears top-heavy because the wheels are lost in the arches. And the boot looks a bit droopy, like someone has bolted a saloon arse onto a hatch body, almost as an after-thought.
Admittedly, there is a way to slightly mitigate some of this - opt for the AMG Sport trim that comes with sport suspension. This lowers it by 20mm at the front and 15mm at the rear, and you also get 18-inch alloys. It helps to hunker the car down around the wheel arches, so there's not such a massive gap at the top of the tyres. But even in this spec, it's still a slightly odd thing to look at.
Our tip? Be very careful choosing the colour. That makes a huge difference to how the CLA looks.
But what about the engine specs?
We had a go in the most expensive one, the 220 CDI AMG Sport (approx £30,000). This engine produces 168bhp and 258lb ft, which means the CLA does 0-62mph in 8.2 seconds. Perfectly respectable numbers.
It also has some impressive eco figures. These run to 62.8mpg and 117g/km, which are competitive with other cars of this size.
From launch, there will also be a CLA 180 petrol with 120bhp and 148lb ft, and other engines will certainly follow. Expect more petrols and diesels, plus an extremely hot CLA AMG at some point.
So what is it like to drive?
Only OK, I'm afraid.
The engine is fine, but nothing more than that. The 220 CDI needs to be more refined around town, because it clatters too much at low revs. Having said that, it's better once you're up to higher speeds because it smoothens out, and the turbo is reactive from low down in the rev range.
But the seven-speed, dual-clutch gearbox frustrates. Especially if you compare it to the latest eight-speed autos from BMW and VW. The Merc transmission is OK if you're pottering, but once you start to demand more of it, things become ponderous.
The three modes - eco, sport and manual - have all got faults. Eco is too sluggish from a standstill, sport holds onto each gear for too long, and manual doesn't react as quickly as we'd like when you pull the paddles. It means you can never leave it in a single mode and be happy with it - you have to constantly switch between them depending on what sort of driving you're doing.
But despite all this, the CLA is very refined on the motorway. It's got pillar-less doors, but you'd never know it because the wind noise is very subdued.
A car to cruise in then?
Er, not if you get the sport suspension. It's tricky to tell on the launch because the roads are so smooth, but it feels like the CLA with the stiffer springs will be a bit of a back-breaker in the UK. Better to go for the comfort set-up, if you can bear how that compromises the looks.
It doesn't sound like you'd recommend the CLA?
Not especially. Merc has created an entirely new niche here, and it had an opportunity to build a car that really stood out. Something to get excited about. But it doesn't look good enough, or drive well enough, for that. It might be a baby CLS in theory, but it's not a baby CLS in practice.