To my knowledge, there is no unsold stock. Hot Wheels fly off the pegs at the local stores and are restocked often. HW produces a given model for a few weeks and it is available in a specific case assortment. Then HW immediately moves on to producing the next case assortment. Usually a given model is available in 2 or 3 colors throughout a given year, but once they are gone, they are gone. Targets and Walmarts will have the most current case assortments and you may find some slightly older assortments at Big Lots, Ollies, Dollar Generals, etc.
Personally, I follow the popular hobby message boards so I know what is coming out and then I grab what I can during the short time they are in stores. That being said, I have a ton of extras, so let me know how many you are after and maybe I can help you out.
Eric
