One thing you could try is to get a Bluetooth transmitter, and hook up the aux cable to it, and then pair the Bluetooth transmitter to your e-Golf's head unit. Then the music from your iPod would play from Aux > Bluetooth > Head unit.
Amazon has a Bluetooth transmitter for around $20: https://www.amazon.com/TaoTronics-Bluetooth-Transmitter-Connected-Transmission/dp/B074QLB1Y7/ref=sr_1_5?keywords=add+bluetooth+to+ipod&qid=1558645976&s=gateway&sr=8-5
If you wanted to keep the transmitter powered, you'd also have to get a 12v USB power adapter and run a USB charging cable from the 12v adapter to the Bluetooth transmitter.
It sounds a bit of a kludge, but I don't see a reason why it wouldn't work.