It does make a difference as they do not use the same filter. The carbed car should also list two filters needed. If it lists 'per car quantity' as one, be wary. The only filters I've seen available at my local FLAPS have been rigid filters. On the stock ZS carbed TR8, the easiest way to change the air filters is to remove the air box entirely, then undo the wire clasps and change the filter.
Some sites list the same filter for the TR7 carb, TR7 FI, TR8 carb and TR8 FI but there are three wholly different filters. I believe that both the TR7 and TR8 FI models use the same filter. Not 100% on that though.