I can handle this edit for you guys. Just PM me call or email, you can find my contact info here:
http://forum.x-cart.com/showthread.php?t=61845
Minfinger I think the other thread you responded to:
http://forum.x-cart.com/showthread.php?t=44590&page=2 is on the right track to accomplishing this. The code does indeed look like it would work in the current version. To get it to display on the invoice as FiberGuy suggested would take a little more work but definitely be possible.
I think this mod is good enough to me to be included by default. It doesn't make sense to inform the customer what method they used, what type of card would be much more valuable info.
-Mike