Hi
Having completed this interior swap this afternoon, i just thought i'd share this topic, having searched it myself many times and not finding a definative answer if the mk5 Golf interior actually fits. These seats were taken from a mk5 Golf GT TDI.
The front seats do fit straight in without any need to modify in any way, as i found on searching this. Ensure you remove the negative on the battery however before removing them to save the airbags from potentially popping.