Aux heater?

My wife and I both have 15’ Tdi sport wagons. The first winter I burnt up the wiring on my electric heater. Repaired under warranty, but 3 weeks of waiting on parts each time. This year, the ground wire and element burnt up in my wife’s car. Dealer has had it for three weeks and still waiting on the heating element to arrive. I believe it’s caused by a faulty ground to the chassis. Has anyone else had this issue? Dealer swears I’m the only one! This year it’s out of warranty and to the tune of $850. Is it possibly I bought the only two sport wagons with bad ground wires?

bad chassis grounds happen on vag cars in general. should be practice to clean the ones under the hood every few years. many electronics