I had a hard time getting a replacement AWD kit. (I got a defective one for Xmas) After I finally got my replacement I did a little research and here is what I found out. The Xmods were more popular for Christmas than RS thought. And there are particular accessories that are in demand, the Berings, Lights, and AWD kits are the top three. These were sold out all over, from most stores and online. It could be as late as march for some of these accessories to filter their way back to the stores. That could take longer depending on production or online/phone orders.
A local RS got some motor upgrades and Tool Kits in last week. I picked up a Stage 1 Motor upgrade and 1 tool kit. (They did not have any tool kits available before christmas) So have patience and the accessories will become available.