I carry sometimes, though I would carry all of the time if possible. My job prohibits carrying firearms or having them in company vehicles, so that means the majority of the week I am without my gun. I can't leave it in my truck either because I park my personal vehicle on company property and leave it there for days at a time while I take the company vehicle home.
Are you able to at least carry a knife or pepper spray with you while in the company vehicle? I carry all three (pistol, knife, pepper spray). At least if you carried spray or a knife you have a way to defend yourself or others. I'm a big fan of having pepper spray with me when I carry, because I feel having a non-lethal means of protection is a good idea if you have a lethal means.