IDSkoT
5,000+ posts
Resonating Reticular
x2 ^-^my favorite kind of terminal cup is the spring loaded one's.
As for the terminal cup: A terminal cup is a terminal cup... it's just how pretty you want it to look. I went to a local audio shop and got two terminal cups for $6 bucks. You just cut out a hole depending on the shape of the terminal cup (mine was in a circle, so I just used a hole-saw) and put it in... I put a nice little bit of silicone on the 90 degree angle to make sure it was sealed.
NOTE: Make sure you set up the wires before you silicone the whole panel down e_e