Definite BS. Absolutely no need for a ‘tech’ guy. You’re right. Just intimidation tactics. I think you can still reject the car now but check this out. If you felt pressured into accepting it, then again, they’ve broken the Protection Regs. And then there’s the discussion you may have had with the dealer about the idrive 7 at the time of ordering.
Here’s the link to the regulations so read through with your brother as he’ll be there. Perhaps a call to Citizens Advice as well might help. These supplement the Trade & Descriptions Act
https://www.legislation.gov.uk/uksi/2008/1277/contents/made
Keep remembering that your with this car for three years.
? I will be remembered for nothing but had great fun doing it ?