My new (to me) 1998 legacy 2.0 gl doesn't have a slide out cup holder between stereo and heater controls on dash, it looks like I've got a blank piece of plastic instead,is it possible to swap one with a higher spec model? Any help appreciated as this is of course very important

Should be although I'd hunt around ebay and that as new ones are 50-60 quid !

Do you have one in the centre console instead ?

I see no problems, just easy solutions... :P