Depending on what other mods you have done?
The list goes :
- Boost and EGT gauges ( should be done before any mods, including EGR plate)
- EGR plate
- Dawes valve
- Needle valve
- Catch Can
- Bigger exhaust
- Performance chip
- Better intercooler
- Better intercooler scoop
- Glow plug timer mod
There is more.
Out of that list that is a must I will say...
- Boost and EGT gauges ( should be done before any mods, including EGR plate)
- EGR plate
- Dawes valve
- Needle valve
- Catch Can
For engine longevity.