Did you buy this from a Chrysler dealer or a used car lot? If lot.. they fed you some lines. I think the RER was the top of the line radio. Most NAV antennas I have seen mount just under the top panel for the dash, near the defog vents. Yes, You are missing the mic. Mr CD1 should be able to tell you what you need if you give him the RER code and the year of the vehicle. Did the dealer tell you what year the radio was since it was not your original radio?

We bought it from a Lotus dealership, and according to them they had no idea the radio was not the original radio, who knows if that is true or not. Anyhow, Mr. CD1 did tell me what I need, now it is just a matter of getting the Lotus dealership to pay for it, lol. Worst case, I am out about $100, as that is what the parts cost. I can install them myself, so we shall see. I thank everyone for their assistance and all the responses.