Amid the brain-addling procession of interviews that a Geneva motor show obliges the typical motoring hack to carry out these days, it’s nice to sit back and answer a few questions for a change.

That’s what I found myself doing in conversation with Andreas Bovensiepen, CEO of BMW’s best-known satellite tuner Alpina and who, it turns out, is a man very concerned about the future for diesel-engined performance cars in the UK.

BMW Alpina’s main Geneva unveiling is the new petrol-powered B5, but the forthcoming equivalent D5, expected at this autumn’s Frankfurt show, will likely be much more important to UK buyers. “We sell 80% of our diesel models in the UK,” Bovensiepen told me.

“So what do you think the British government will do about them? Will they be penalised in London and other big cities? If you were me, and you had to decide now whether you would develop another all-new Alpina D3, would you do it?”

I did my best to reassure Andreas that, in spite of all the noise and uncertainty that surrounds diesel in the UK right now, the appetite for cars as multi-faceted as the D3 and D5 isn’t likely to wane any time soon.

But you can see his predicament. Alpina isn’t a company that can afford for so much of its model range to flop on the back of kneejerk regulatory changes.

He admits they’ve considered branching out into tuning BMW’s increasingly impressive petrol-electric plug-in hybrids, but he doesn’t like the weight penalty they carry or where it’s carried (“too high and too far back,” he says).

BMW Alpina is is a great company, making great cars, that has managed its business very skilfully over the years, and it deserves to succeed. “I’ve already had a visit from van Meel today,” Andreas says, talking about his opposite number at BMW’s in-house tuner, the M division.

“As normal, we are in the market with our B5 some time in advance of the M5. And I could tell him about the little problem we encountered with the new G30 5 Series.”

“At very high speeds, there is a big enough pressure wave above the car to make the sunroof lift slightly out of its setting. In the B5, we fitted a small spoiler to break up the airflow. But it was news to him because they don’t develop cars beyond 250kmh. We have a very open relationship with BMW and with BMW M; we are friends and allies.”

The new B5 looks every inch the brilliant super-saloon we’ve come to expect from Alpina over recent years, but it’s no small departure for Alpina.

It’s the first car of its kind to switch to all-wheel drive as standard (although Alpina has made it a priority to make the handling feel as rear-biased as possible), it’s on Pirelli tyres instead of the usual ultra-low-profile Michelins and it’ll hit 62mph from rest in just 3.5sec, they claim - and although acceleration claims like that are increasingly common, I still can’t get used to them being associated with two-tonne saloons.

Needless to say, I can’t wait for a go. And as equally unnecessary as it may seem to point out, I trust that any change to diesel-specific UK car taxation will be done with enough notice so as not to expose car makers such as Alpina too harshly. They deserve better.