Imagine you're on taxable income of £120k and have two chidlren in nursery. Currently you get no help with childcare costs from the government. From my own experience it's ~£6000 subsidy per child.
You can currently take out an EV salary sacrifice scheme for ~£600 per month (pre tax), and that brings your taxable income down by £7200. Put another £13k in pension. Boom, you're now getting £13k in pension p/a, and your car is effectively free, because you get £12k back in childcare subsidies.