The discs are new despite the surface rust. I assume the garage cleaned behind the disc before putting the new one in place, i'll check non-the less anyway.

your brake sliders appear to be seized,hence the line of rust still on the inside part of the disc.This may be causing uneven braking or the caliper siezing on.Does the noise get louder when you are cornering,if so then you have a knackered wheel bearing.The wheel studs hold the disc in place by the way,it only gets stuck in place by rust.

By the way,the two holes are for removing a siezed on disc by skrewing 2 m8 bolts into them.

when they are put on the discs are loose, they tighten with the wheel nuts, if you look closely you will see the holes are threaded, this is because after years of them being on there and not moving, they rust in the gaps and become really tight, basically they are there for you to screw a bolt into when replacing them, you wind the bolts in evenly to to pust the disc off, the positioning of the holes are just different depending who made them.

so as long as the discs are tight when the wheels are fitted and tight, then all is good.

I see what your pointing at in the picture. Never noticed it before, the noise doesn't come into play when cornering, it always tends to pop in during straights, specially along bumpy roads or hitting a hole in the road ( not all the time. )

Cheers

fair enough, learn new things everyday. I'll see if I can get hold of a proper jack, have a look at the subframe bushes just to be safe, aye I made sure the wheel was firmly on after checking it the day.

hummmm, that'll teach me to not read the second page, both my points had already been answered, lol

ahh well, can never have to much information.