Radio Accessories

I just got the Lemons 5 watt radio kit and I am looking for a few accessories to go with it.

Here is what I'm looking for

1.  A Male-Female nexus cable extension(ideally a coil cord).  I want to run a straight extension in between the driver connection and the car loom.  This way when my drivers forget to disconnect the radio they do not destroy the long expensive cable in the car.  Just the short extension piece.

2.  I'm looking for an adapter to go from the IMSA nexus connector to a 3.5mm headphone jack so drivers that have rental gear can use a set of headphone earbuds.  Or an adapter that goes from the nexus plug to a female double plug like on the radios. Because we have the earbud kits that come with the radio.

3.  What are the good ways to hold the radio in the car.   I think I saw like a bag thing in the past?

Does anyone know where I can these things?  I called rugged radios and they said the the IMSA connectors uses a different type of wiring than a regular headphone jack.  What have team done when they have drivers that rent helmets?

Also  I am looking to install the helmet kit in my Bell Sport SA2015 helmet.  It does not look like the cheek pads are not removable.  Does anyone have any tips for installing the kit? Thanks