Warning, this subject is old (5119 days without answer)
antp
There is the same "problem" for other VW models: the convertible versions of Beetle & Golf should have different codes.
But to keep things not too difficult to manage we use the most common code.
Other car maker do that. For example the Renault Mégane III for non-European markets has a different code.
cibup
Wikipedia's Volkswagen New Beetle, at "Body Styles" make the distinction between Type 9C (Coupé Europe & others), Type 1C (Coupé North America) and Type 1Y (Convertible). However at IMCDb are everyone listed as Type 9C (Coupe and convertible, european and american)
Somebody has some information about?
(Sorry, my English is not very good)