My Model 3 turned up earlier than expected and I don't have a home charger fitted yet. I popped into Sainsburys to use a pod point charger but can't use the cable supplied by Tesla. Do I have to buy a complete new cable - or can I buy the bit short bit that has the 3 pin plug on and just change that. Looked around internet but looks like I will need to spend about 140 quid on a full cable.