The first roll up windows Intermeccanica put in their Roadsters (conv.D) started with the first Roadster built.
The first Speedster with side windows, (not side curtins)is the car that Mart drives throughout Europe. The IM VIN for that car is 13333 and I think it was finished late 1999 or early 2000.
My car was built late 2001 and delivered early 2002, the IM VIN is 13356. Coincidentely, that is also the VIN that CA DMV is using on my SB100 registration.
Intermeccanica speedsters built in Vancouver all have IM VIN numbers starting with 13 and the Roadsters start with 14.