There were indeed Italian versions of the both Subway and Ice Show
released exclusively for Italy;
that were slightly different than the US Versions of these same AAB
pins.
At least the BackGlasses are different,
not 100% sure about how they awarded Extra Balls.
If you look closely the USA versions of Ice Show
they have 10 numbers showing for balls to play
http://www.ipdb.org/machine.cgi?id=4778
and the Italy versions have a BG with only 5 numbers displaying for
balls to play
http://www.ipdb.org/machine.cgi?id=1263
(I am betting that some of the ice skaters on the Italian BG
would light up to designate extra balls "won")
Same happens with Subway
5 numbers showing on Italian model
http://www.ipdb.org/showpic.pl?id=4777&picno=13102&zoom=1
(with the 5 passengers under the Game Title on the BG probably lit up
for extra balls "won")
but 10 numbers dispalyed on BG for US AAB model.
http://www.ipdb.org/showpic.pl?id=2412&picno=2301
And for CardTrix the Italian AAB is not showing any numbers for Balls
to Play
http://www.ipdb.org/showpic.pl?id=3748&picno=49394
its got 5 little green flags instead ( to show player what extra balls
they won)
with the 5 balls (to play) given at the start of game play,
displayed (but hidden) until back lit;
compared to US version with normal 10 numbers indicating Balls To Play
http://www.ipdb.org/showpic.pl?id=446&picno=10095
Sometimes its kinda fun looking at the Italian model's BackGlasses,
trying to determine how they were able to "slyly" display
( to the player ) what extra balls they earned,
above and beyond the normal balls given at start of the game.
Some times it was flags or balls or stars or star bursts
Or cacti flowers or billiard balls or little fishies.
cheers Pinballtom