Easy plug and play. Instructions were conflicting regarding colour of wires used and left blank. Also conflicting information regarding the Ford setup when using the PAC steering wheel interface. These two items should've been mentioned in one sentence: "Use the Ford SW interface and you don't have to worry about which colour wires will be used in this application".
I now have two Bluetooth Audio inputs, SYNC and AVHP-4400BH, for BT audio streaming. On my iPhone 4S, they show up as two separate 'Airplay' devices. SYNC automatically switches over the bluetooth, but doesn't revert it back once it's done say, taking a call. This has to be done manually. With the SYNC BT audio, since the AVHP-4400BH requires it to input through AV, the screen is black. Alternatively, I can stream BT audio through the AVHP-4400BH, but then I can't use the voice command, and resume play has to be done manually, unlike SYNC's voice command. This may not be the shortcomings of the 54MSFRD1 interface, but if you decide to buy this same setup, this unit is not entirely compatible. Other reviews may say otherwise, but this is the best setup I was able to achieve, with the help of Crutchfield's excellent tecnical support.
Pros: Almost Plug and Play. Had the instructions been clear, it would've been TOTALLY Plug and Play. All wires are there for HU input, AV input, AV output, GPS module, satellite radio module, and others. Couple wires still unknown and not connected, such as the brown wire.
Cons: Despite it advertised as compatible, at best, this interfaces allows 'Co-Existence' with SYNC. With the Pioneer HU and the PAC 543SWRC steering wheel interface, the 542MSFRD1 Interface requires manually switching the HU when SYNC has taken over control say, after a call.Have to hold the Media button to switch the system off SYNC, then the steering wheel controls are back for the HU.