What's my Golf worth? (selling soon!)

[NDT]

Hello all,
will be selling my Golf very soon.
A lot of the ones on autotrader are dealers, so anyone got any thoughts on value?

2003-53, Mk4 GTi PD150 diesel
Metallic black, 5 door
One owner from new.
56000 mainly motorway miles
Full VW service history - just been serviced, new discs and pads front and rear.

It's in good condition - with a couple of minor scratches (a job for chipsaway before I sell her!)
There's a towbar fitted (only used once).

thanks for any views!

[greatgranny]

Whatcar says £9.5k private sale and £8.5k trade-in.