I've had like one respawn, I think. But the rest have stayed empty. Just scan through your map periodically would be my advice. On the overhead map, they always say if they're empty (grey) or full (white).
There's no zodical sign called Nesbitt. GT: Dr Nick 1971
After you plundered them it takes a long time til they become available again, so you can just go ahead and plunder all of them when they become available again. Also, I believe one mission requires you to plunder a warehouse so I guess it could be possible to replay that mission and get more loot, but I am not sure.
Since I am replaying the game again, I will try out the theory and if no-one posts about this by the time I finish, then I will let you know my results.
Gamertag: Volcannon Quote: I HAVE THE SHINIEST MEAT BICYCLE!!