It's not the LED or interior lights themselves, it's the slab of grey plastic that's with them (can't get to my car to take a picture). Pushing that makes my rattle go away. Hopefully it'll be the issue with your car Dave!
The V40 is a good car, but we've just had so many bad things come our way this year that when my wife said "treat yourself, you only live once" I decided to get rid. The rattle combined with the poor mpg (can't get above 60 even when driving economically, never had that problem before!), narrow boot and road noise did it for me. I still think it's a stunning looking car though with awesome seats and with a bit more thought it could be a fantastic car next generation. It's also better than the Audi having driven an S-line A3 this weekend - what a waste of money that car is with everything being an optional extra. Compared to Audi, BMW and Merc the V40 is value for money.
MY15 V40 CC D2 Lux