Addons needed:

1. Sub-Materiel tool https://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=405793043
   
2. [simfphys] Halo Reach Vehicles (Higher quality vehicle models than the following addon, and has chaingun textures) https://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=2282272484
   
3. Halo reach model pack (For damage textures) https://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=753972615

Sub-materiel tool list should look like this https://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=2942818614

All of this will be saved with the simfphys vehicle duplicator, meaning you do not have to do it every time you want a reach warthog
Enjoy!