Duplicate values in Leads Pick List

Duplicate values in Leads Pick List

I am trying to create a Pick List in Leads with the names of a large number of vehicles and models.  When I try to do this I am being stopped from proceedng because there are duplicate values.  I assume this is because the name of the vehicle is being tagged even though there is a different model after each make E.G "ALFA ROMEO 146 3 door hatch", "ALFA ROMEO 146 4 door sedan"
Can any one help me with this?