There is a part of the install that does need drilling into the crossmember to put a bolt through. But When I installed my C4 sliders. I did not have a drill at the time of install, so I never ended up drilling and its been about 3 years now lol. Its been holding up well and never thought about it until I saw this thread and post. I"ll get to drilling it one of these days. But I think it should be fine as it is. Also, I opted to have thread plates to have as a step for my family and any added protection. I also like the look of it.