As unfair as it may seem - if the dealership provided the warranty and are saying that installing these pieces of kit will invalidate it, that's the case. I'm not sure why exactly they have an issue with the MINI Click and Drive system but I assume they perhaps wanted to see the invoice to check if it's genuine. At the end of the day, these bits of tech could cause issues with the car's software and the like if they weren't genuine. As for the Nextbase camera - any hardwired bit of aftermarket kit can actually invalidate a warranty. When readers want to hardwire the dash cam, we often suggest checking with the warranty provider and insurer first as it's technically classed as a modification. If it isn't hardwired, then it isn't considered a modification.

My advice would be to ring the dealership again and ask where you stand as it seems unfair you've bought genuine accessories you can't use. I wouldn't go straight to an autoelectrician without checking the warranty situation first. If you still have trouble, get in touch with MINI customer services to ask why you can't have the kit installed.