Here is the answer according to the Illinois Vehicle Code:

VEHICLES (625 ILCS 5/) Illinois Vehicle Code.
(4) Any personal property belonging to the vehicle owner in a vehicle subject to a lien under this subsection (g) shall likewise be subject to that lien, excepting only: child restraint systems as defined in Section 4 of the Child Passenger Protection Act and other child booster seats; eyeglasses; food; medicine; perishable property; any operator's licenses; any cash, credit cards, or checks or checkbooks; any wallet, purse, or other property containing any operator's license or other identifying documents or materials, cash, credit cards, checks, or checkbooks; and any personal property belonging to a person other than the vehicle owner if that person provides adequate proof that the personal property belongs to that person. The spouse, child, mother, father, brother, or sister of the vehicle owner may claim personal property excepted under this paragraph (4) if the person claiming the personal property provides the commercial vehicle relocator or towing service with the authorization of the vehicle owner.
And if from an accident...

(5) This paragraph (5) applies only in the case of a vehicle that is towed as a result of being involved in an accident. In addition to the personal property excepted under paragraph (4), all other personal property in a vehicle subject to a lien under this subsection (g) is exempt from that lien and may be claimed by the vehicle owner if the vehicle owner provides the commercial vehicle relocator or towing service with proof that the vehicle owner has an insurance policy covering towing and storage fees. The spouse, child, mother, father, brother, or sister of the vehicle owner may claim personal property in a vehicle subject to a lien under this subsection (g) if the person claiming the personal property provides the commercial vehicle relocator or towing service with the authorization of the vehicle owner and proof that the vehicle owner has an insurance policy covering towing and storage fees. The regulation of liens on personal property and exceptions to those liens in the case of vehicles towed as a result of being involved in an accident are exclusive powers and functions of the State. A home rule unit may not regulate liens on personal property and exceptions to those liens in the case of vehicles towed as a result of being involved in an accident. This paragraph (5) is a denial and limitation of home rule powers and functions under subsection (h) of Section 6 of Article VII of the Illinois Constitution.

After a vehicle has been at Reynolds Towing Service for 10 days we write to the Secretary of State (SOS) to find the last registered owner. Once we receive the owner information from the SOS we send a letter to the owner letting them know that we have their vehicle and they have 10 days to claim the vehicle.

This process usually takes a month and a half to two months depending on how quickly we receive the information back from the SOS. If the vehicle is not picked up after the 10 day period then we file with the SOS for a junk or salvage title. Once we have filed for the junk/salvage title it is too late to claim the vehicle. Once the salvage title is received the vehicle is sent to the junk yard. All vehicle owners are responsible for towing and storage EVEN if the vehicle is not claimed.

A relocated car may be claimed with a picture ID, payment of cash or credit/debit card and your keys. The picture ID does not have to match the name on the vehicles registration card, we do not accept checks and don't forget your keys!

Parking spaces in some parking lots are leased to vehicle owners, other parking lots are reserved for customers or employees. Property owners request a towing service to hang relocation signs in their parking lots so that unwanted or violating vehicles can be towed. The Champaign and Urbana city ordinances allow for these violating vehicles to be towed away or relocated without the vehicle owners knowledge or permission.