If running main engine, may be a manifold exhaust or baffle leak being blown back into the cab. Can you smell it while driving?
Crack window, get...
As noted above, check out S & S. Good company too. Ask if they run by the girlfriend's place. Might as well kill two birds with one stone.
Call and ask for Tony in recruiting, he'll set you up.
Call and ask. They may be able to work something out short term. Jersey is about the closest you'd get to home. Rental car from there and back to...