I can't common in detail on the drilling as mine were pre-ordered and fitted prior to delivery. But it definitely looks like some drilling is required although i would suggest, done properly, the corrosion risk must be minimal. Yes they are pretty rigid, but I would say that there's little risk of damage from bumps/obstacles etc - certainly not experienced anything like that myself. They're a very neat finish, give some added protection and look really good on the car - so I would definitely recommend getting them fitted.