Stuck in a bit of a pickle at the moment

I have a late 18 plate Tig 190 DSG owned her since new, was 2 years old as of last week. Cars immaculate and detailed monthly

I currently have the car over 4 years directly with VWFS it will have cost me approx £18.5k @ 40k Mileage over the total term (£380 a month) .
I'm debating buying the car at the end of the term from VW directly, i have been told they go off trade price when it comes to pricing so if VW dealer has car up for 23k they will offer me at 20K etc.
Just not sure if it's a good idea, what have others peoples experiances been with them?
Would i be better getting a settlement figure now, or waiting another 2 years and see what factors affect the value ? e.g. electric grants from gov / new tig shape etc.
or just handing the car back as is ?
I really wanted to get an electronically deployable tow bar fitted and start towing with her, that's £1250 @ VW directly... so trying to think carefully really !
Appreciate the help on this !
