As days in the office go, this was certainly an odd one. I should have been sitting at my desk, tapping out another motorhome review, but instead found myself reading a mysterious – and, it must be said, rather eleventh hour – invitation from Hymer to fly to Stuttgart and attend something called an ‘innovation day’. Intriguingly, the invitation advised the wearing of ‘warm clothes and sturdy shoes’.

Interest more than a little piqued, I accepted the invitation and instead of driving the usual three hours home after work, found myself braving the rush hour traffic en route to Heathrow. A few hours later, I was sitting, slightly bewildered, in my hotel room just outside Stuttgart, wondering what the following day would bring.

What the following day brought was, initially at least, a brand new (not to say rather sinister-looking) black Mercedes-Benz Viano with privacy windows, which whisked me off to Mercedes-Benz’s development facility at Untertürkheim. Here, I was ushered into a large, but secluded room, where I was issued with a name badge and the world’s strongest coffee, before being left to mingle among the other journalists – all apparently German.

The room was dominated by three display motorhomes: a glorious-looking Hymermobil 520 D from the 1970s (which had either enjoyed kid-glove treatment its entire life, or, more likely, been extensively restored); a brand new Hymer ML-T Crossover built on a jacked-up four-wheel-drive Mercedes-Benz Sprinter base vehicle positively bristling with knobbly tyres and a huge air intake snorkel; and the skeletal underpinnings of a Sprinter chassis cab. A fourth, and unmistakeably motorhome-shaped vehicle nearby was hidden beneath a huge drop cloth. Curiouser and curiouser.

All the while, we were surrounded by beautifully-lit partitions awash with colourful marketing images of Hymers gone by, together with triumphant information about the various safety systems with which the very latest Mercedes-Benz Sprinters are equipped.

Eventually, a mournful-sounding gong echoed around the room, and the assembled throng sat down to the first of three ‘workshops’, this one detailing the history of Hymer’s long association with Mercedes-Benz. Translators were on hand to repeat the words of wisdom being imparted, and it was all very professional.

I must say that it was all very interesting, too. I mean, I wasn’t aware that the very first Hymermobil only hit the showrooms as recently as 1971, and that the motorhome in question – the 550 – looked, rather oddly, like a caravan plonked on top of a Mercedes L 508 chassis. Probably because that was what, in essence, it really was – integrated it certainly was not. Similarly, I’d never heard of the 1978 Hymermobil 900, either, a 7.5-ton A-class of dubious aesthetic appeal that looked suspiciously like an American RV.

Next up – following the sounding of another funereal gong – was a masterclass on the Mercedes Sprinter (which can be summed up thus: launched in 1995, facelifted in 2002, replaced by the second-gen model in 2006 and then again by the third-gen model in 2013), and then finally a detailed technical description of the latest Sprinter’s various driver aids. These include Crosswind Assist, Collision Prevention Assist, Lane Keeping Assist and High Beam Assist, together with (deep breath) anti-lock brakes, traction control, electronic brakeforce distribution, hydraulic brake assist, adaptive ESP, Load Adaptive Control, Rollover Mitigation and Roll Movement Intervention, Enhanced Understeering Control, Automatic Brake Disc Wiping, Hillstart Assist and Trailer Stability Assist. Really and truly, if you manage to crash a Mercedes-Benz Sprinter with that little lot in your corner, then you really shouldn’t be on the road.

And then finally, The Big Reveal – and, we suspect, the real reason behind the event: the new Hymer ML-I. It transpires that Hymer’s new A-class warrants an awful lot of the aforementioned driver assistance (though not, intriguingly, the Crosswind Assist), and that we would get to experience them for ourselves at Mercedes’ own test track just up the road.

It’s a curious place, comprising a couple of straights and a short banked curve, together with simulated rough road surfaces, rumble strips and a vicious-looking wading pool. But where many such facilities are secreted out in the countryside well away from prying telephoto zoom lenses, the Mercedes base is slap bang in the middle of a town.

Our first exercise was seeing the Crosswind Assist in action. A bank of industrial-sized fans shrieked into life, and we were invited to drive a variety of Hymer ML-Ts past them at speed. Sure enough, the various computer systems did their thing, and the necessary wheels were automatically braked to maintain stability. By way of comparison, the team put a rather elderly Hymer van conversion through the same simulation, which was duly blown unceremoniously into the adjacent lane.

Next up was a demonstration of the Distance Warning Assist. This involved us driving more ML-Ts closer and closer to a vehicle in front (actually a bale of hay on a trailer covered in Mercedes van tarpaulin) before jabbing the brakes. Unlike similar car systems, the Sprinter doesn’t do the braking for you automatically, but does intervene if it senses you’ve not hoofed the anchors hard enough. The result is akin to two giant invisible size 12s stamping on the brakes.

And finally, a graphic demonstration of the Sprinter’s inherent stability, even when subjected to unutterably rubbish driving. Yet more ML-Ts were drafted in, which the assembled scribes then took in turns to drive into a coned-off trap at 60km/h (just under 40mph), then steer violently left, then violently right, all without touching the brakes. Not a few of the motorhomes ended up on three wheels, but all negotiated the chicane without drama.

Clearly, the unveiling of the new Hymer ML-I was the big news on this event, but the history lessons were fascinating, and sampling the latest Sprinter’s driver aids was certainly eye-opening. Mercedes-Benz might be in the minority in terms of motorhome base vehicle here in the UK, but on this showing at least, it looks like it will be actively seeking a bigger share of the market, longer-term.