not sure on estate rear panels but looking at the mk3 above the mk4 bumpers should bolt straight on and vica versa but front end it is

both wings
scutle
full front panel including bottom bit
bonnet
grill
indicators
headlights
and if you wanna do a proper job so it looks like true mk3 bulkhead and inner wings

if doing innner wings then you will need a mk3 top engine mount if not and going to for a mk3 engine then don't forget to get a mk4 top engine mount as they are different

hope this helps

depends really how far your going with it thanx alain