I have seen some cars with heated front screen button in these positions, is it possible I have the wiring for it and just need a switch?

Don't think you'll have it. Look very closely at the windscreen and if you do you will see very fine wires in the screen.

The wires are just there due to the universal loom being used.
If you had a heated screen then the button would be there and not just a blanking plate.

Sent from my SM-G965F (S9+)

heated seat wiring

Heated seat woring plugs would terminate at removeable blanks on the outer flat spots and are more rectangular and larger.

Sent from my SM-G965F (S9+)

Thanks guys, so I should be ok to take them out if the blanks and put my own switches in for fog lights or something.

I am fairly sure that 1 of those wires is for the esp warning ( if it gets switched off  it lights up ) and the other is illuminated if the passenger airbag is deactivated via the deactivation switch inside the glovebox, ( again if fitted )

If you remove the plug and hold the plastic up to a bright light you will see an outline of the relevant emblem on the front of the blank.

Indeed.
From left to right are passenger airbag deactivation light, front demist, rear demist, esp.
The blanks are a universal fit in either of the 4 spaces but active buttons & warning lights have slight seating lug / groove / connector variations that match a particular hole (and therefore a particular switch) so they can't be muddled up.

Sent from my SM-G965F (S9+)

air bag deactivation thats what id go for