This problem has been tackled before......It's a common fault.
If the glass is the wrong shape it cannot physically 'push' the rubber out to the aperature(where it's supposed to be)
A lot of the aftermarket glass is poorly shaped too,result...water leaks.

To be told it's not a problem is wrong!Judging by the fact it leaks seems to confirm this......

As IsolationRide said, if it's a show truck re-do them.
If you don't want to go down that road,your only option is to try and seal them in situ.
There are many sealants available,try contacting another 'reputable' glass shop. They would be able to suggest something suitable.Personally I would use a urethane based sealant.That's my preference.
As long as it's not silicone! eek


1950 Chevy Advance Design 3100 in Scotland
In the Stovebolt Gallery
More pix on Flickr.
I've definately got this truck thing in my blood ... my DNA sequence has torque settings
"Of all the small nations of this earth,perhaps only the ancient Greeks surpass the Scots in their contribution to mankind" Winston Churchill.