Not very much. It really doesn't matter what kind of powertrain you have in your vehicles, the biggest part of the manufacturing process is everything else that makes up a vehicle. Frame, suspension, brakes, doors, windows, seats, dash, cabin interior, lighting, electronics, safety systems, sensors, testing, inspection, etc. etc. etc. On top of that, plenty of automotive plants these days get fully-assembled engines and sometimes driveshafts as well from other factories for efficiency and bolt them into vehicles rather than doing build-up from scratch.
I've spent quite a bit of time in vehicle factories of several OEMs. I would estimate that less than a quarter of an average factory line is used for powertrain.
*Note: Parts here means only powertrain parts. Tesla, for example, is notorious for having massive delays in repair parts availability for things like doors, trim, and windows.
VW group is pushing EVs via all of its major brands (VW, Audi, and Porsche at the very least). These models are also not being treated as one-off afterthoughts (GM style) or cars with a totally different design language from the core brand (BMW i3 style), but match the design language and performance characteristics that I would expect of each brand, all with increasingly impressive battery ranges.
They have the global manufacturing/supply chain well figured out, design modular chassis that see use across almost every vehicle in its brands' portfolios over each decade, and this translates to getting nearly-unbeatable pricing from intermediate parts suppliers.
Tesla has a lead on both the battery and software, but while other brands are catching up significantly on these fronts, Tesla does one thing better that I don't see any other manufacturer daring to tackle: vehicle purchases. Every stage of buying a car at a dealership is worse than the last, and maintaining these frustrating middle-men and their shopping lots full of unsold vehicles adds unnecessary cost to every vehicle's consumer price.
To date, EV sales are still a bit of chicken-and-egg, and Tesla does have a clear charger network advantage in parts of the world. But EV sales are a very small fraction of overall automotive sales, and until that changes, any doom and gloom on the traditional automakers is still exaggerated.
Tesla built GF1 in the Reno desert because, at the time (2013) [1], they forecast that at 500k/vehicles a year (which they're almost at), they would be consuming worldwide battery cell manufacturing capacity. And here we are with everyone else playing catch up trying to eek out the batteries they need to deliver EVs to compete against Tesla.
[1] https://www.tesla.com/sites/default/files/blog_attachments/g...
Well you wouldn't have to worry about this regardless unless you are the competition. But otherwise it's like saying "I'll worry about EVs when I can charge them in 3 minutes at every corner". If you worry only when the threat already materialized then it was pretty short sighted. Which is an ironic attitude considering we're literally talking about companies ignoring reality until it hit them in the face and the threat materialized.
Demand ^ Emphasis mine.
VW is not behind most of the market; they're leading it. Tesla's huge early lead will stick around for a very long time, if not indefinitely. They'll become a player as big as VW and Toyota. But, these other manufacturers will catch up and begin to compete just fine.
There's plenty of manufacturers that should be concerned (Ford being the biggest one). VW (and by extension, Audi, Porsche, etc) is not one of them.
Personally I have been very positively surprised of Tesla after owning one for a few months and I it would take very much to make me give up all it's niceties but I think the Polestar is a sleeping tiger when it comes to sales. It seems to generate a bit of grass root buzz in the EV communities here in Norway.
So some of the incumbents are finally taking the shift to new power trains seriously, but there will be slaughter for those who can't keep up in the long term.
They also spend €13.6 billion on r&d every year.
It just seems to me these legacy automakers who haven't done much at all are in for a rude awakening. If battery costs keep declining, anyone who isn't using a battery is going to get smoked on costs, and this is in a carbon-tax free scenario. In many economies with environmentally friendly policy, we should see EV's smoke ICE vehicles on cost MUCH sooner.