Scrap it and write off the extra £200 you'd have gotten for dealing with the type of people who buy £400 cars.
It's on Gumtree and FacebookIs eBay worth the cost seems expensive.
I sell cars like this on eBay, they always sell within the 7 day listing very easily. Even non running cars which need trailering.
In the end I sold it to a couple of Ghanian guys who tested the car by bringing a CD of music and turning it up really loud on my driveway.
Not a pleasant experience all round.
Do you do a classified ad or auction ?