[Perfectlap]

well on hard to find stuff like this allot of people employ the ebay email alert. You can set up it to notify you as soon as someone lists the clears and if there is a buy it now you'll get first crack it.
and try some forum searches for Litronics or group buys, if someone just upgraded maybe you can make them on offer if they still have the clear halogens. The proactive approach might help.