I use a Topeak Office trunk bag - it's like a briefcase, and requires a Topeak MTX modular rack. I added some extra padding, have had no problems with laptop failure, but I haven't dropped it either. I have a 15.5" wide Dell Precision, it seems that it is about the biggest that can fit. One downside, since the bag extends over the side of the rack, it limits pannier choice to a bag that has the hooks at the very top. Topeak does sell a "Super Tourist" rack that has a pannier mount point below the top.