Oh I know.... but then again if I were a thief attempting to do this I most likely wouldn't care. Based on todays state of business I can only imagine how easily this is done.

So far from this post I could:

Look up the history of the vehicle.Insert
Make a false registration plates with another vehicles number.
Restamped  the frame number and a place a new VIN plate on the chassis.
You could "force" a title on it through the court system.
Can have a key made for it.

and this my friends is how "Chop Shops" thrive and continue operate.....

Well, the "thief" would have to be the dealership, if they would make a key without seeing proof of ownership.
One other thing you need to consider is that you are talking about a tracker/sidekick.  How desireable are these to "clone" or be stolen for a "chop shop".  I can think of several other vehicles I would rather clone or chop before I would a trackick.
So going back to my original post, I still think the person is being paranoid about giving up the VIN to make sure the parts will fit.

dude.... I couldn't agree you more!

I can't imagine doin this but then again I'm no thief and I don't consider most theives to be overly bright!

Although.... I sure have scavanged alot of Zuki parts in order to get mine to it's current state.


Yep..... PARANOID....... 

I must be paranoid.
In my Chevy fullsize I have the VIN COVERED with an index card under my dash cover.  
Why?
What you mentioned about chop shops.  I'm not too worried about my Chevy work truck, but same theory applies as if it was a Z06 vette or anything with a hot-rod engine.  The VIN decodes the engine.  
So if someone wanted to steal my truck because they know that the 8th digit is a T, and the T means it has the 5.3L V8, then they know that they can sell that engine for "X" number of dollars.  They can decode all the vehicle options and determine whether or not it is worth it for them to steal.
That's for "smart" criminals.  I'm talking about real "pros" in the auto theft/chop shop business that actually look this kind of stuff up.
Because on the other hand, you have the smash-and-grab scumbags that just want to go for a joyride or mess with you for no reason at all.

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.

I think this is a bunch of what ifs and worry about nothing. The guy was just asked to give the vin # not the car. for any of the scenarios to work, you would have to have both. You are more likely to have your car stolen and wrecked in a joyride or chopped up. It's is extremely unlikely that your car will be stolen and the vin tampered with or all the other theoretical examples done unless the vehicle in question is a very high value to make it worth getting caught and going to jail.