In general most dealerships, regardless off brand, will answer this when asked about installation of non-oem equipment in their cars. However in this particular instance (audio upgrades) the chances that a well-reputable installer is able to fudge anything up when doing such an upgrade are VERY...
I wouldnt rule out all other good/better brands because someone else has used a particular setup before though. A lot has changed in this particular field the last few years and there are now a lot of other brands that offer the same and/or better solutions.
I for one, would have a long chat...
Knowing this business...in my country... Any well-reputable shop should be able to get you a decent setup that fits your budget and demands. Personally i would then tend to favor wellknown speaker/amp brands.
To be more precise, in Norway electrical cars are currently excempt from all kinds of VAT and customs charges, while combusiton engined cars have allways been heavily taxed.
As a direct comparison...on Porsche.com the starting price for a Taycan is currently 82.700 USD, while the Panamera...