Crane ignition....must use capicitor if extending wires??

PittSpeed Automotive PittSpeed Off Topic
1

from the Crane directions;

“A filter capacitor on the 12 volt supply is recommended if the CD unit power wires are extended, the battery is located in the trunk, or solenoid valves drawing more than 10 amps are used. Use a minimum 38,000 microfarad (uF) 16 volt capacitor across the 12 volt supply (heavy red wire) and chassis ground near the CD unit.”

  1. what is the point?
  2. can i get this at Radio Shack?
  3. it ties into the positive and ground wires right?

thanks guys