The video teasing of the upcoming 2013 Cadillac ATS compact sedan continues with the fourth installment of the series that focuses on the engineers behind the development of the car with which GM hopes to compete head on with the BMW 3-Series and Mercedes-Benz C-Class.

The rejuvenated wreath and crest brand stresses that all engineers working on the upcoming ATS were "handpicked based on their roles in developing other top Cadillacs" and "how well they can drive and evaluate cars on grueling test tracks".

For some reason, General Motors is hell bent to show us what it did with the pug-faced 2013 Cadillac ATS prototypes on the famous Autobahn and the Nürburgring racetrack in Germany this past summer.

After a general teaser and the first episode, Cadillac has now released the second part of its video series, which documents the team of drivers and engineers that put Cadillac's new BMW 3-Series saloon contender through its paces.

Hop over the jump to get a look of the new video.

An official photo that was published allegedly by mistake on Cadillac's public site earlier today, gives us our first glimpse at the production 2013 XTS luxury sedan, one week ahead of its world premiere at the Los Angeles Auto Show.

The picture was captured before it was removed from the website by a reader of Jalopnik, which then confirmed its authenticity with Cadillac.

The production model is almost identical to last year's XTS Platinum concept study that was displayed at the 2010 Detroit motor show. In fact, from this angle, the only noteworthy styling changes appear to be limited to the headlamp and fog lamp assemblies and the larger and more practical mirror housings.

It’s been roughly two weeks since Cadillac dropped the first teaser video of the 2013 ATS at the Nürburgring and now GM has the released the first full installment of its web series dedicated to the development of the premium compact sedan at the so-called "Green Hell".

The Detroit-based company's goal of course is to associate the ATS with its German competition, and specifically the new BMW 3-Series.

It may have taken a while, but if anything else, General Motors is showing signs that it has learned its lesson from the German competition and has even brought the game to their "backyard" challenging its rivals on the Nürburgring racetrack.

While Chevy's team was trying to record a fast lap around the "Green Hell" with the Camaro ZL1, Cadillac engineers brought the upcoming ATS sports sedan to the "Ring for a two week-long trial in September.

GM published a new video that provides us with an inside glimpse of the testing that took place and which you can watch in the clip below.

Here's another chance to take a look at the upcoming 2013 Cadillac ATS, GM's answer to the executive compact sedan segment dominated by the likes of BMW's 3-Series, the Audi A4 and the Mercedes-Benz C-Class.

And just in case you're wondering, the introduction of the ATS will lead to a larger next-generation CTS to better compete against cars like the BMW 5-Series and the latest Lexus GS.

Our scoop photographers captured the 2013 Cadillac ATS while testing in Europe. Even though the prototype is clothed in camouflage, we manage to get a taste of the car's size as well as Cadillac's edgy design language with prominent creases running along sides and the front and rear ends of the ATS.