I thought all new cars had to have a locking petrol cap.
Also a locking cap for a MOT pass,
Just a thought I may be wrong
That's what is said but the interpretation may be open, although any key required must be available for the tester. No mention is otherwise made of key locking though. Our modern Mini has a simple non locking fuel filler cap but it's behind an oval hinged cover which itself is solenoid locked by the BCU when car is locked.
I wonder therefore if the twist to lock feature of the CX series filler cap qualifies in itself without having a key lock.