Thanks for the information. Until I saw the Speed of Sound insert set listed here I did not know it was a thing. I have sets of this release, in binders, and an unopened hobby box. I never came across any of the specially numbered (# of 10) cards. My hobby box lists only 3 inserts: Leaders of the Pack 1:35, Silver Speed 1:6, Fan Scan 1:72. There is no mention of the Speed of Sound inserts. It seems like the packaging would advertise all of the "chase" cards. Anyway, I always appreciate the members time and information. Regards, Dave