In my Chevy fullsize I have the VIN COVERED with an index card under my dash cover.
It would be interesting to know the legal ramifications of covering/concealing the VIN - since it is a federal requirement that it be visible. I guess LEO has other things to do, so no one really cares.
On a parallel but slightly different note - in Guyana, we are required to have our "road license" displayed (I believe this is equivalent to the little self adhesive tags that get stuck to US license plates to indicate that they are current or valid) - due to a recent redesign of the road license, the vehicle owner's name & address is now clearly visible, and at least for me, a security risk, since it allows anyone who sees the vehicle parked in the city to find it later at my home.
Several drivers have taken to covering that portion of the certificate whilst leaving the remainder on display - LEO can verify that the certificate is current and corresponds to the vehicle's license plate, which seems to be all they care about, since I have been pulled over a couple of times, and no comment made about it.