Not for me, the amps i'm using have the pass thru feature so I connect the amps accordingly, no line driver needed in my setup.
My only point was going completely wireless and not using a head unit. There are a lot of way to configure your setup, I just choose to go wireless. The other cool thing is I can take the same Ipod in my sandcar and use it without having to put a head unit in it.
Forgot, I also have a Bluetooth receiver in my toy hauler so again, no head unit and the same wireless Ipod setup.