Thanks for reaching out!
We are expecting to see deliveries of car top boxes from Thule and Yakima in the coming weeks and months. As soon as they become available for purchase they will be visible on REI.com, so we recommend checking there periodically. Do you have a particular model and size you were looking for? With a bit more detail we may be able to narrow down the window of time we are hoping to be back in stock.
Hopefully this helps, thanks!