Did this mission 3 times, i had let the priest keep his guns before fyi
got the docs, killed the guys, talked to napa, got in the car
1st time round was playing co-op with a friend
i switched to driver seat and it booted the npc guy out :p
drove down to the coast road and drove all the way down to electrogradasdfz
got in the chopper with no scripted driving bits
chopper flew off over land, got shot down
went to napa base, talked to the guy over satphone and mission ends
get the mission completed screen, click continue and... no new mission shows up
do it again offline, this time the car doesnt bug and i get teleported around and eventually kicked out roughly where the chopper crashed first time
then the same thing happens, complete mission but no new missions show up
3rd time was the same as second time except playing co-op with friend again
the endmission command got the next mission to show up tho so its not a problem but thats a new bug i havent seen anyone report in the thread so far :p