Unless you're driving an LX, nothing to do while you're in there regarding a roof rack; LCs are all done up top. Unless you do it wrong and push a retainer clip loose and lose it in the headliner.
You might consider adding some sound deadening while it's down. You don't have to cover every corner and crevice to achieve good dampening results. Large swaths of foiled butyl on the big exposed portions of single-layer sheet metal can do a lot. Especially if you plan to run a lot of stuff on top that would increase wind noise. Stock and unloaded, it's fine and doesn't need any help.
Cascade Audio is cheaper than Monstaliner by about a 1/3rd and shipping up from OR isn't a deal killer.