Lol nope, they are not common i found one not that hardlock this noob rage post
THIS IS NOT BETA THIS IS SPARTA
Special encounters are location-based, to my knowledge (...) It's a pretty awful system because if one person in a faction finds the zone/zones a special encounter can be found on, they can just farm the crap out of it with alts
This was changed about half a year ago. There is smaller chance to find them, but you can get them in various places.
Jovanka has dropped many hints already in this thread that should make it easier for you to search for these new or old special encounters. Would you really search for a truck known to be in lost ruins in the middle of the desert for example?
It's not just about where... It's about the certainty of whether or not Luck or PE checks are done for the encounter.
I have been out of touch with actual development for some months, but back then, the Luck Stat was never considered in the likelyhood to find such an encounter.
I am sorry I can't give you a more clear answer, more kind and knowledgable souls like Jovanka surely can give more clear statements.