This is the information verbatim from the Illinois State Police website pertaining to reciprocity.
"No. Out-of-state residents who want to carry a concealed firearm on their person must obtain an Illinois Concealed Carry License to lawfully carry a concealed firearm in Illinois. In order for out-of-state residents to be eligible for an Illinois license, their state’s concealed carry license laws must be substantially similar to those of Illinois. The Illinois State Police will establish rules to identify the elements necessary to meet the substantially similar requirement.
Out of state residents are granted a limited exception to lawfully carry a concealed firearm within a vehicle if they are eligible to carry a firearm in public under the laws of their state or territory of residence and are not prohibited from owning or possessing a firearm under federal law. This rule became effective immediately.
If the non-resident leaves his/her vehicle unattended, he or she shall store the firearm within a locked vehicle or locked container within the vehicle in accordance with subsection (b) of Section 65 of the Firearm Concealed Carry Act."
Do not get out of vehicle to pump gas, or for any reason with gun