2006 RRS HSE

Heated front windscreen... I don't have one...
Its a spanish reg car, but im off to a cold climate soon and thought this may be a good idea.

Due a replacement soon due to a chip..

If I paid the extra for a heated one, are the cables already in place? And will the connection be there for the heater switch on dash?

wires would be on the inside if present. Remove the A pillars to see. I expect they are there.

More importantly, you need:

A climate control panel with the front screen button
Probably need a GAP IID tool to enable it.

It's probably worth having fitting, even if you need to wire it up yourself, with an aftermarket switch. I know not ideal, but depending how many cold mornings you will be doing worth having.

I had this issue on a 2012 Jag XF (so probably very similar). Check the fuse box for the 2 relays and fuses (one for each side). I tried for a year to get someone to code it and failed.
On checking the wiring diagrams it was actually activated by putting a earth on 1 wire (that switched the relays on) so I bought a timer off ebay and built my own. Pretty simple to do. 2021 L494 D300MHEV Autobiography
2019 Discovery Sport D180 HSE