Yeah, odds are you will need some kind of interface. Not necessarily the OEM-1, but something at least. There should be a few brands out there to choose from by now. Basically what those little interfaces do is to add a convenient connector plug and a small low-power amplifier to your outputs.

Note that if you buy the OEM-1, it comes in three parts:

1. The empeg-side of the cable harness.
2. The OEM-1 box itself.
3. The car-side of the cable harness.

Remember to buy the correct doohickey for item number 1, which is the line-level RCA plugs.

And don't forget a dash fascia adapter of some kind.

here is a photo gallery of an OEM-1 interface installation session.