Chicago's weather is hard on cars — salt, potholes, and freeze-thaw cycles all take a toll. A few checks go a long way before you buy.
Ask for the title in the seller's name, not someone else's. A mismatched title is the single biggest red flag in a used car deal — walk away if the seller can't explain it clearly.
Check the undercarriage for rust, especially around wheel wells and the frame rails. Surface rust is normal here; flaky, structural rust is not.
Run the VIN through a vehicle history check if the price justifies it. It won't catch everything, but it catches flood damage and major accidents more often than not.
Always test drive on a mix of surface streets and highway speed. Listen for noises that go away when the radio comes on — sellers sometimes "forget" to mention those.
Meet in a public, well-lit place during the day, and bring someone with you if you can. Chicago has plenty of safe public parking lots near busy shopping centers that work well for this.
Finally, get a mechanic's inspection if you're spending real money — a $100-150 inspection has saved plenty of buyers from a $3,000 mistake. Most independent shops will do this same-day.