Cheers.
I've just been reading up on it here which suggests a damp microfibre should fix any smears.
It shouldn't matter, as it's usually laid on C1, but I intend to try it out this weekend, so I'll try it in top of the existing wax (Natty's White, Red and Blue - I couldn't decide which use so layered them all ), I'll also strip a panel or two and apply straight to the paint and report back in due course.