My basic idea is that other than for achievements nobody really visits the bank! Also there are a massive amount more weapons than armors and vehicles, although the workshop addresses this a little more cant hurt! In the bank you could sacrifice one weapon to jam/blow/smash open a safety deposit box, the safety deposit box will give you a random reward which could be an item of varying use, 5% boost to energy, health or stamina, cash or in vary rare cases 2favour points or 2 skill points(less than 1% of the time). You would also recieve XP for blowing a box, I am thinking on a similar amount as challenge assist XP, sacaling with level. This would have a 4 hour cool off time so realistically could only be completed about 4 times a day. The items received would be mostly low level and not great but with a chance of getting a really nice item, obviously again this would be dependant on level. I think this would give the bank tab a little bit of purpose and could also come with seperate achievements for entering the boxes a certain number of times with explosives, knives, guns and living weapons(sumo/lion etc). These rewards would have to be rare enough to make a big difference in-game but good enough to be incentive to blow the boxes!