i just used plain black electrical tape when i wired up my sub

 

Otherwise special cookies for them

G/L on your install

 

while you're there, ask them for some headlight fluid. Sometimes it starts to leak when you mess with the audio components.

Don't let this happen to you:

 

lol

 

use the 3M electrical tape that has the yellow label on the inside. it sticks much better than regular 3M tape and can withstand higher temps. you can find it at most hardware stores and in all home depots on those little end cap displays.