Q: Exhaust and radiator.

This sounds like potentially a catalytic converter issue in addition to broken exhaust mounts. The smell of fuel along with the overheating suggests that the catalytic converter may be clogged. As you may know the catalytic converter converts toxic exhaust gases to cleaner exhaust. When the catalytic converter becomes clogged, this does not allow the car to expel the toxic combustion gases (think of a clogged sink) which then backs up into the exhaust system causing overheating and very rich fuel smells as you describe. I would suggest having an expert from YourMechanic come to your home to diagnose this overheating issue and make necessary repairs including replacing your catalytic converter.