Annoying hub - wheel noob question.

[Mk3 AAA]

I'm probably posting this up a bit soon, but ran into an issue today and it's making me scratchy.

Putting Audi wheels (TT wheels 5X100) onto VR6 hubs, fronts fit like a glove, but the backs don't fit (all wheels are the same), I replaced the hub/discs in the back from ECS not long ago (OEM VR6), but the old ones I have lying around likewise don't fit into the wheels.

Any experience before I take a series of pretty angry looking power tools to either the hub, the wheel, or just generally to the side of the car :O .

The wheels have a small rise on the inner surface that rests on the hub (like a lip that sticks up just before the very back of the wheel....hard to explain), so that might need to be lopped off, but all wheels have it and it's not an issue in the front.

Has anyone else experienced variations between front and rear hub sizes?

I need to measure and see what isn't 57.1, but any similar experience?


I should add, I tried them without the centre caps and they still didn't fit, it could be the axle cap too, Vortex etc aren't a lot of help.... will get the ruler in the light.