I would imagine that not many garages would even take your car as a part exchange im afraid !! Not trying to slag off your car but its usually more hassle than its worth for them to try and shift it on as most cars like this will end up being put to auction, they have to pay to get the car put to the auction in the first place then they pay auction fees etc etc so it can soon mount up and they could possibly end up losing money.

Best thing i would say is to try and sell your car privately even if it is for peanuts and then you have a better chance of buying something else at a better price as always get a better deal if you dont have anything to trade in as dealers always prefer a straight sale !!

Hope this helps.