I drive a big f*ck off black truck, so I'm no help here
Anyways though, £1500 for the car + £150 for VED + £400 for insurance + £1000 for fuel = £2500. Is it worth driving a shed (that's likely going to need odds and sods fixing) for that kind of saving? Although obviously in yr2 the costs plummet, but then more risk of expenditure to repair... If it were me, I'd at least buy a fun shed so that you get some enjoyment from it.