We forgot to order the RCA cables and speaker wire when we ordered the major installation components from Crutchfield. We went to the local electronics store and found a good deal on speaker box cover material, but the wire prices were a high per-foot price. We hit the local Wal-Mart and found these installation kits. The 1,200-watt amp kit was $29, and the add-on amp kit was $24. We think these two wiring kits are a great deal..