Advice I’m wanting a Octavia vrs found one but has slight mould on the white on rear seats any advice on what to look out for please 

Damp under the carpets, which is likely from either -

 

Scuttle panel drains blocked letting water in via the bonnet release cable grommet.

 

Door card membrane ripped/missing/ not sealed fully behind a door card after work being done.

 

Or, it mightve been sitting closed up for a while, in which case every car goes like that..

 

Dry it out and steam clean the upholstery then aircon bomb it to fully disinfect..