I own one. When I received it I found out that its 4 'rigging' holes didn't exactly fit my R18 Classic side case holes.
I wrote them several email (at least 3 times) about that issue and they never came back to me.
I needed that rack for my Summer road trip and decided to solve this myself. I straightened the bar with a hammer to make all holes fit well.
However, it's adding a bit of space between the side cases and the motorcycle. The screws are not long enough. Bought some longer ones at the drugstoren but it's not the exact same thread. So I went to my local BMW dealer and they've very gently given me 4 slightly longer screws (+1 cm) that rigs perfectly the whole thing.
The rack is quite solid. It's just that I had to use a hammer before mounting it

I hope this helps.
Cheers,