My 2016 430i started leaking coolant and put it in a garage as I have little knowledge about finding the cause or fixing it.

According to the garage they have ordered aftermarket part twice which didn’t fit therefore they have to order the genuine part from bmw. Which is on back order and will be made available sometimes in middle of December.

I’m just trying to find solutions as I need my vehicle soon and don’t want to let the car be in the garage for more than a month. Anyone have any advice. I really appreciate it. Based in UK