My dealer investigated this when we had an order for the 5 but the whole roofrackgate thing kicked off, he said apparently there was no way to fit one to either the 5 or the ZS EV. Not sure how true this is as most of the stuff he told us was wrong. He did really wanted us to buy the car and I said I only would if it could have a tow bar fitted so I'd have thought he would have checked pretty thoroughly.