I'm late to post but anyone asking for a VIN number is a scam.

For vehicles, the SOP is to respond to every single inquiry to let them know that you will not be paying for a fake VIN check and that they must come and see the car in person before negotiating.

I've recently sold two cars on Craigslist without issue, but encountered dozens of scammers trying to get me to pay for a fake vin check.