Duane,
1.) I vote for the type of decal that can be seen from both sides and printed on clear film that will be placed on the outside. (Reading from the inside will be in reverse, but you can see thru.
2.) 2.5 " diameter should be plenty of size. Windshields on cobras are small enough without anything on them.
3.) "Member" should be included on all decals, as we are all members, so why not include from the start. Maybe insert in the blue /green circle under "Club Cobra."
4.) Self addressed stamped envelope for return of decals a must; check for payment can be included went sent to whoever is handling.
5.) I'll sign up for 6 of them.
Terry Lee