I found something out.
I'm LVL 32 with $200,000 apartment and money trucks DO NOT spawn at all for me. However after loosing connection a server (Every one just left at the same time) about 1 min later an armored truck icon appeared on my map. So i went to explode the truck i got (2,000RP, $0, 0JP) and a 4 star wanted level.
So it seems that you MUST play on a server where every one has a $200,000 apartment/for every one on the server to have unlocked the abilitie to destroy armored trucks. Other wise LVL 10's could probably end up blowing the trucks up them self's in-game and getting a bunch of easy RP when there only LVL 10's when your men't to have a $200,000 apartment.
Short way of saying things
Play SOLO to get armored truck icons or be super lucky and make sure all 16 players have an $200,000 apartment.
So badly implemented kinda. But it makes sense but it sucks.