TonyD
When warm/hot, ethylene glycol (antifreeze, coolant) smells sweet.  There is
probably a leak around your rear heater (fairly common) and may be due to
(1) deteriorating hoses that connect the heater core to the cooling system
(or depending on your perspective, the heating system!) or (2) a leak in
your (rear) heater core.

Mark Williamson
Denver, CO
88 Wolfsburg Weekender