Seems pretty straightforward to me. If a car or a commercial vehicle is business use only all the VAT is recoverable by a properly registered business (its’ not always been this way). That means that if the Grenadier is classed as a car by HMRC you can still recover the VAT if usage is business only. The tricky bit is being able to demonstrate no private use. That’s where the pool car type is sometimes created to mask the real use or where the car is genuinely a pool car. Salary sacrifice for car operating costs might also be an option for some businesses.
Trickier still because for a lot of us with smaller own businesses the vehicle is also a lifestyle choice. For me I keep it simple. I buy the vehicle and charge business use to my business, I suffer no BIK and that way I get no challenge from HMRC, but do also suffer if I rack up heavy mileage. The official mileage rates also need updating for current fuel and running costs.
Vehicle disposal is also simple, no VAT to deal with but if the vehicle suffers heavy depreciation you pay, but if I’d put it into my business the business would pay, though it’s still my money so I take the cash hit either way. The Grenadier should suffer quite light depreciation so overall costs should be acceptable for what is an expensive vehicle. Defo better than a Range Rover.
I spent my working life in leasing - VAT and BIK important in the UK with the company car/perk position, total cost of ownership more important elsewhere. It’s is not a good plan to give HMRC a reason to investigate you.