First I was worried to drill holes in the roof but I think with a good sealant which I used should be no problem.
Removal of the drill shavings is very important as every one knows ,I guess. The instruction are very well explained.
( In proper English , and you must be mechanical minded & the right tools to fit it). The seller was very helpful and the communication excellent .
Hyundai is asking a lot more for the same Product.