I decided to box up the repeater so that it was primarily self-contained.  This would simplify moving it from vehicle to vehicle.  I additionally wanted to be able to turn the box on its side to that it could sit on the floor behind the passenger seat in a sedan if not placed in the trunk.  So the mounting of the repeater as well as the rest of the stuff inside the box could be kept intact in either type of "mounting".  The batteries are handled differently.

The repeater is screwed into and completes the forth side of the box.  The box height is abut 3 inches taller than the repeater to accommodate the router, the 12V controller and miscellaneous cabling.  The box has large holes drilled into the sides and back primarily for easy cable penetration as well as ventilation if either the power supply an/or RF power amplifier fans are switched active.

 The UHF duplexer/antenna is optional as I typically use a "leaky" resistor dummy load on the transmitter connector (at 1 watt RF output) and spike on the receiver connector, good for about 1/4 mile.  I use a default 10 Mhz split without a duplexer with no issues.

Use of batteries and the 12V controller enables continuous operation without regard to the vehicles "start" battery.  I have an optional 8 foot cable that I can power pole into the mux with a DPDT switch for router on/off as well as repeater on/off at the driver's finger tips.  I have had  a couple cellular issues that did require a reboot, so this approach is handy while in motion as well as flexible depending on the current "install".

I get about 12-14 hours on a single 22AH SLA battery including the normal TX time (1.1 amps idle and 2.4 amps TX).