What happens if p/x is worth more than new car?

[tyranical]

Genuine Question.

I am looking to downgrade, I normally part exchange to save the hassle but the car I have now is worth around £2000 more at p/x price than the car I am interested in replacing it with.

Is this going to cause a problem as I doubt many dealers want to pay people to take a car off their hands when they are trying to make money from selling a car to them?

Cheers