Add suitcases as a carryable object for people that can be used to contain Cash/drugs/Weapons/oil whatever it is thats being dealed or transported to add more to the rp Experience
As Canadian mentioned we used to have a backpack system, however it was very buggy and exploitable.
We don't believe it to be worth the time required to either fix or remake it. The inventory you have is bigger than most servers, not to mention trunk space and item banks exist. Be more conservative of what you store on you.