I've been watching EV conversions happening for a while, and I'm entirely up for it when parts get to sensible prices, but <£1000 is off in lala land. A Nissan Leaf motor on its own costs more than that. The article conveniently forgets some substantial hidden costs for the sake of a headline.
It is an eminently sensible option for the future, rather than replacing all combustion-engined vehicles with new EVs, but until parts are common enough to become commodity items, they are still going to be prohibitively expensive for 99% of motorists. A Tesla swap in to a D2 for example would be in the region of £15K just for parts, to get motor, control electronics, and enough batteries for a reasonable range. No one is going to spend that, but £5K and it becomes more realistic. Even to swap my Mum's Beetle Cabrio using Nissan Leaf bits is going to be in the order of £10K by the time it works, which is just silly. Yes, I have looked in to both extensively
We need more EVs on the road so that 1, the parts are produced in higher volumes and get cheaper, and 2, more of them end up crashed and broken for bits, and then we also need government subsidies or incentives to do the conversions in the first place. Only then will we see this becoming mainstream.