RemetzCar is ambitiously planning to build 20 units, the first of which is in production thanks to a commission from a Dutch shooting brake collector and EV enthusiast, says the company. They intend to unveil it in March, and it'll likely have a custom interior considering what the company usually does when converting a vehicle. From what we can tell, RemetzCar mainly builds limos, and they look decent enough. Moreover, they have a broad range of donor vehicles – we saw everything from a stretched Fiat 500 to several Mercedes-Benz wagon-limos.
The process seems to start with an angle grinder and end with a lot of welding. You can see how they built the hearse below; it's a safe bet the process for the shooting brake will be very similar.