Capt. Obvious

Do X51 cars have a special designation in the VIN, or is it only confirmable by looking at the option sticker (assuming you're not able to see the engine to confirm the headers/intake/heads)?

Nedster

The VIN will be no different then any other regular Carrera. It's the case even with 40th AE cars that had it stock. My car does not show it even on the hood sticker as the installed option. But it is there I only saw it when i asked the dealer where it was serviced and sold new to print out everything they had. There is ways to get these reports online as well.

knfeparty

Do you have an aluminum intake or a plastic one? That's the easiest way to tell as far as I know.