Okay, so sat and no phone prep, it's by far easiest just to run a new mic cable. The antenna cable you're talking about is SMB. The cable will need to be a female plug on the MULF side to mate up. I assume it'll need to be female on the antenna side, too, but I didn't use the stock antenna. I bought a $5 RP-SMA duck antenna, SMA-SMB adapter, and SMB female to SMB male extension to go from the mulf to the adapter to the antenna.
If you've got the antenna already, can you post a picture of the connector on it?
RE: range to the front - if you leave the antenna in the trunk, it'll probably work fine. But it IS highly directional and the coverage pattern is optimized to be in the cabin where it normally goes.