Sharing a vin number is safe. To get a vehicle history report from places like lemonchecks.com or Carfax, you need to have the VIN # in order to perform the search. Instead, use Google Voice, which allows you to select a different phone number from your own, but still accept calls and texts.
What is an FEIN? | Patriot Software (Delia Todd)
Is It Safe To Give Out Vin Number On Craigslist Wallpaper