just recently an awfull smokey smell has started coming from the heater vents its a bit like a clutch burning or new brakes being bedded in - really choking sometimes - also the windows are fogging up and wont clear & when i wipe them its slightly greasy and not condensation - can anyone help please

 

Sounds like your heater matrix has gone, probably hot antifreeze you are smelling and wiping from your windows.