Just go get it, you now possess it. You don't own it or have title, but you possess it. It depends on how and where it was abandoned. If it is on a public street it is the responsibility of the local authorities. If they know about it and care, they will mark it so they can tell if it stays past some defined time. Then they tow it away, contact, or try, the last known registered owner, they may or may not threaten that owner with tickets, towing, and storage fees. They then auction it off. Mebbee your bid will win. If you attempt to tow it off, you will be charged with auto theft. You might be able to track down the owner, get permission and a title before towing and then assume any parking tickets it has received. If on private property you may be able to title it. There's some 'depends.' DMV regs. vary from state to state. Your best bet is to contact them, go online; call them, learn a whole new repetoire of elevator music, here about state services'just an easy phone call away,' here repeatedly that no one is available to take your call; go in person, take a book, I suggest War and Peace. Generally what DMV will have you do, if the car is on truly private property which you own or have permission of the owner to act as an agent (as opposed to a private 'public' property, a mall parking lot where other rules apply) and your state allows it is; demonstrate that the car is truly abandoned,evidinced by condition, time, or other factors; make an attempt to identify, locate and contact the last owner and/or lien holders, usually a certified letter to address on title (VIN leads to title); there will be a specified time period waiting for response or after lack of one; then DMV might title car in your name.

This is civil, especially if the vehicle is on private propterty. you will need an attorney. If the vehicle is on public property, like the side of the interstate, the police will normally tow these vehicles away for liability. Most of the towed vehicles are sold at public auction to the highest bidder. look for notices in your local newspaper of call your local police department.