Ooooh, this isn't so much an investigation as it is a treasure hunt.
All you really need to do here is drop some enticing leads and then throw some opposition in the way. Leave a trail of breadcrumbs for the PCs to follow. Either by asking around a bar or doing some digging in the matrix or metaplanes or something, maybe the hear that there was this elf with a distinctive scar asking about the map, and they start looking for him.
Then when they follow up on that lead, they find a location where he usually hangs out. Maybe the go to a contact who points them that way. Maybe they look online and find a recent photo of him and can recognize the locale. In any case, they're off to a bar to or something to find this guy, only to learn he's already moved on, AND that there are some Evo goons there looking for him. One of his buddies in the bar can point them to where the dude was (PCs are now on the move once again) and once they're in the city and start asking questions, someone can eventually tell them, or they can witness via one of the rigger's scout drones, or something along those lines, that the dude was nabbed by S-K, then the PCs need to bust him out. He of course, has a new lead for them, and so on and so forth, until you get to the actual map.
Also, do you mean you actually allowed a player to take Addiction (Cooking) as a quality?