No wiring. The seat switches are an integrated part of the circuit board behind the grey panel, so no easy retrofit possible.
However, fibreglass heating mats can be added to the seats although requiring a fair amount of dismantling. If you look at the seat plastics there are already some cut outs where you could install the switches.
Not beyond the competent diy'er. Plenty of videos on Youtube if that is your thing. While not exactly the same, this should give you idea of the work involved.
View: https://www.youtube.com/watch?v=d_rSXz2Z1Vw