Addtional/auxilary heater

[Stijn]

Since my car is really taken its time to heat up the coolant and the interior i was looking at its cooling circuit. Although the thermostat is my main suspect, i noticed that some cars are equiped with a additional heater. I know it is designed to heat up the interior faster. Is there a easy way to found out if my car is equiped with this thing without taking the left front mud guard off? VIN VF7**************[VIN obfuscated, can be read by forum staff]