does anyone know if it is possible to have aircon retro fitted by a dealer to a new shape 1.9 Octavia classic and if so the sort of costs involved?

Dont think dealer would do it but there are companys that would do it for you. I nearly had it done on my Audi A4 Tdi and it was going to cost £1500 + vat. It was cheaper to part ex the car for one that had aircon as standard so thats what I did. I cant remember the company off the top of my head but If you want I can go and have a look and see if I can find the quote. If you do get aircon or swap your car for one that has it you will never look back its fantastic.

As said above will proberbly be cheaper to change your car, looked into it about 6 years ago when my then current car didn't have it. Was to expensive so swaped cars!

Yeah you are looking at £1,500 minimum mainly because of the labour involved in removing the dashboard etc. Even at that your Skoda dealer wouldn't do it and you'd have to go to a specialist. The specialist's system controls wouldn't be like the Skoda ones either. These guys are professional but it would still be noticeable that its retrofit and it may even reduce the value of your car come trade in time not to mention Skoda possibly not honouring your warranty.

If you really need it i'd change the car.