Gumtree is FREE advertising so people are just shoving anything and everything up there. Not a good place to sell cars any more if you have a decent vehicle I think. Better off on Carpoint. Gumtree is moving with the times though. Leave your ad up there with no activity from you and they will delete it.
As we all know, the economic climate is a tad cloudy lately which makes for some really good bargains on Gumtree. I advertise my rentals on it and do OK.
Sometimes you have to wait for the cheap crap to disappear before your value for money item becomes the logical choice.
You can't beat FREE.
Edit:- Any ad on the tree that starts with "Hey Guys" is bound to be some backpacker selling off some crap.