How do you add/change VIN in VMS using SMOD

Hi All;

I have finally figured out how to create a car and move it along using Actions.  Now, I have an issue.  When I create the car there is no VIN attached to it.  I have read that you need to use action SMOD to add the VIN.  I have add SMOD action to my control matrix and have vehicle attribute VHVIN added to action SMOD in the "Define Additional Data for Vehicle" configuration.

However, when I execute the SMOD action, I don't get a pop screen or any data entry screen that lets me enter the VIN.

How do I do this without javing the Dealer Business Management (DBM) add-on installed.

Thanks

Stephen