if you’re using bars with t tracks (thule wingbars) do the t track bolts stay in the roof box / bag and when you want to fit and remove do you just slide it on / off the bars? (like fitting a thule bike carrier)

thanks

Because the bag isn’t rigid, you might have a job aligning/sliding it on, particularly the first time to get the bolts/holes to line-up. Should be easier once you’ve got the position of the bars sorted.