Got the car back, pretty much 3 weeks without. The BCM had filled with water and was deceased. Part arrived on Monday and is fitted. Stung me, all in, with fitting, VAT and a call out when the problem was originally spotted, £728. BCM was £350, vat about £100, the rest was labour. Not how I wanted to kick off the festive period. Still have to program the keys with Nissan apparently.