new old 318is e36 99year

Hi all. Only baught a 318is. Could any one tell about condensation on inside in cabin
E36 year 99. Also if this sparkplug ngk. Bkr6equp is siitable for car

Water leaking into the cabin can have several points of entry:

Around the front or rear windshield (if they were ever replaced)

From a clogged sunroof drain (very common)

Failed vapor barrier inside the door panel (also very common)

Leaking heater core (feel the carpeting under the dashboard....if it`s damp/wet, that`s your suspect)