Just find them. There are 3 general stores on each map and at least one won't show up until you're within a few feet of it.
I have found all 3 in the Frontier and in Boston, but the one in North Boston still isnt open for convoys. with the others, they were available as soon as I walked in. glitch maybe?
Have you liberated the area it's in? Only thing I can think of...maybe.
I havent reached the point where you do the Liberation missions (im in sequence 6) I guess its not too big of a deal as I have 5 stores I can trade with, but i tend to have OCD about video game things like this lol --- I do the best Chewbacca impression EVER!
Nah, not necessary at all. You make enough money to buy everything from just normally playing the game. Even if you want to get 100% on the game, you can manually trade a few skins to get the last little bit. The money I have on my character after getting 100% is almost exactly equal to the amount I gained from trading.
I never do those Convoy or Ship stuffs, and I just barely had enough to complete game, the main mission that is. --- What'the matter? Disliked my grammar? http://24.media.tumblr.com/tumblr_m5vz0vCbdS1r1g5kzo1_500.gif