The PetReg Renault Premiums we had when I worked for Calor Gas had working Cigarette Sockets for your phone/sat nav etc, they just had to be unplugged and switched off in the refineries, there was an isolation key for the night heater.
I would imagine it should be the same for any PetReg Vehicle.
Are fuel tanker drivers allowed to have a regular radio in their cabs?
I see a lot of them wearing earphones, this might indicate they are not even allow to have a regular radio fitted.
Heads up on Certas energy guys, lots of rigid jobs nationwide on 6 month contracts, good luck to those who apply:
www.certasenergy.co.uk/careers/job-board/