So guys what can I do about this?
Remove surface rust then coat with what?
I could ask Murray motors for you as they did exactly this when my evora had a recent annual service?
Looks like you had a small stone trapped between disc & pad.
PS If that happens, can often be shifted by braking when reversing.
PPS Ditch the locking wheel nut whilst you can too
Please that would be really helpful.
wheel and brake check today so will take a look at pad. Cheers Rob
Don’t forget to tighten all the bolts back up!!!
That is the reason for the check. I DIDNT touch the one that was loose so IMO Lotus missed the thread lock of it hence me doing all four corners again today as it is too risky not to check. 
Question asked, watch this space!
In the past I’ve used black engine lacquer having cleaned all the rust off 1st
best answer tho…ali bells
Murray Motors reply received already (they really are top blokes 
)
This is carried out at all our services … The brakes are washed drilled filed and buffed then painted in high temp paint (If the calipers are painted then these are also polished )
Hope that helps Damon.
Thanks Tim
POR 15 mate.
Get it from ‘Holdens’ (Good Ozzy name!!!)
Yep, remove the rust with sandpaper or whatever… I then used masking tape and then painted POR 15. Silver so looks cool!
There is a simpler way… never drive in the wet… NEVER in the winter salted roads!!! 